(The 10th amendment of the US Constitution created a patchwork quilt of state laws related to driving, which is why Jalopnik sorts through the red tape to bring you detailed guides to driving topics such as teenage driving, speed limits, open containers, dehorsing and lemon laws.)
We we're tempted to just limit this guide to stating that, unless necessary, you shouldn't use your cell phone while driving (A CB Radio is much cooler anyways). But that would make some of us (ahem, Wert) serious hypocrites. There's no state with an all out ban on all types of cell usage, though approximately half of all states have some sort of laws on the books.
City laws vary so we're going to focus on the current level of statewide cell phone bans. In states with jurisdictional laws we'll list the cities included. It is important to note that Chicago, the city with one of the strictest cell phone use policies, is being sued because of the law. The attorneys that filed the suit are claiming that the ban hasn't been properly enacted. The suit doesn't undermine the legality of enacting such bans, however.
Novice Drivers
The District of Columbia and 17 states currently have laws focused on novice drivers, generally meaning those with learner's permits or restricted/novice licenses. These laws almost always include a full ban on persons driving with learner's permits from using a cell phone in a non-emergency situation. New Jersey doesn't allow drivers under the age of 21 to use a cell phone while driving if they don't have a full, non-graduated license. This is all premised on the theory that young drivers are bad enough as it is without yet another distraction.
Preemption Laws
For various reasons, some states don't allow local municipalities to create cell phone driving bans. States like Florida don't allow local municipalities to make any sort of laws related to the use of motor vehicles, which would include cell phone driving bans. Kentucky, on the other hand, specifically states that city or county governments can't impose driving bans. Localities are explicitly allowed to create cell phone driving bans in six states (Illinois, Massachusetts, Michigan, New Mexico, Ohio and Pennsylvania).
School Bus Drivers
This is sort of no brainer, but only 14 states and the District of Columbia currently have a ban on School Bus drivers talking or texting in non-emergency situations. While we understand why it's a common occurrence, we're a bit surprised to see less states taking action to avoid disasters (we can't imagine there's that strong of a school bus drivers union).
Hands-Free Sets
There's much argument over whether or not hands-free sets are safer, though we tend to doubt it. The few moments we've lapsed on the phone while driving it wasn't because we were looking at the buttons it was because we were paying attention to what was being said. Be that as it may, it's legal to use a cell phone with a hands-free kit according to state laws (city laws may vary).
Primary v. Secondary
As with many laws, including seat belt laws and open container laws, enforcement is either primary or secondary. If it is a primary enforcement law, that means you can get pulled over just for violating it. If it's a secondary law you have to also break an additional law before you can get cited. For example, it's a secondary law in Colorado therefore you'd have to run a stop sign or speed before getting the additional ticket for violating the cell phone ban.
State Laws
These are as of 12/01/2007 and apply only to state-wide laws. Where noted these laws don't go into effect immediately.
Alabama
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Alaska
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Arizona
Hand-Held Devices: Allowed
Bus Drivers: Banned
Novice Restrictions: None
Enforcement: Primary
Arkansas
Hand-Held Devices: Allowed
Bus Drivers: Banned
Novice Restrictions: None
Enforcement: Primary
California
Hand-Held Devices: Yes (as of July 2008)
Bus Drivers: Banned (including transit operators)
Novice Restrictions: 18 and Under (as of July 2008)
Enforcement: Primary
Colorado
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: Learner's Permit
Enforcement: N/A
Connecticut
Hand-Held Devices: Banned
Bus Drivers: Banned
Novice Restrictions: Learner's Permit and Under 18
Enforcement: Primary
Delaware
Hand-Held Devices: Allowed
Bus Drivers: Banned
Novice Restrictions: Learner's Permit and Intermediate Licenses
Enforcement: Primary
Florida
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Georgia
Hand-Held Devices: Allowed
Bus Drivers: Banned
Novice Restrictions: None
Enforcement: N/A
Hawaii
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Idaho
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Illinois
Hand-Held Devices: Chicago Only
Bus Drivers: Banned
Novice Restrictions: Under 19 and Learner's Permit
Enforcement: Primary
Indiana
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Iowa
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Kansas
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Kentucky
Hand-Held Devices: Allowed
Bus Drivers: Banned
Novice Restrictions: None
Enforcement: Primary
Louisiana
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Maine
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: Learner's Permit and Intermediate License
Enforcement: Primary
Maryland
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: Learner's Permit and Intermediate License
Enforcement: Secondary
Massachusetts
Hand-Held Devices: Brookline
Bus Drivers: Banned
Novice Restrictions: None
Enforcement: Primary
Michigan
Hand-Held Devices: Detroit
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Minnesota
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: Learner's Permit and Provisional Licenses for the first 12 months after licensing
Enforcement: Primary
Mississippi
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Missouri
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Montana.
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Nebraska
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: Learners Permit and Intermediate License Holders under 18, includes Blackberry and other wireless devices
Enforcement: Secondary
Nevada
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
New Hampshire
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
New Jersey
Hand-Held Devices: Banned, Including Text Messaging (As Of 3/01/08)
Bus Drivers: Banned
Novice Restrictions: Learner's Permit and Intermediate Licenses
Enforcement: Primary
New Mexico
Hand-Held Devices: Santa Fe
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Additional Restrictions:
New York
Hand-Held Devices: Banned
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
North Carolina
Hand-Held Devices: Allowed
Bus Drivers: Banned
Novice Restrictions: Drivers Under 18
Enforcement: Primary
North Dakota
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Ohio
Hand-Held Devices: Brookyln, North Olmstead and Walton Hills
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Oklahoma
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Oregon
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: Learner's Permit and Intermediate Licenses (As of 2008)
Enforcement: Secondary
Pennsylvania
Hand-Held Devices: Lebanon, Conshohocken and Conshohocken
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Rhode Island
Hand-Held Devices: Allowed
Bus Drivers: Banned
Novice Restrictions: Under 18
Enforcement: Primary
South Carolina
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
South Dakota
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Tennessee
Hand-Held Devices: Allowed
Bus Drivers: Banned
Novice Restrictions: Learner's Permit and Intermediate Licenses
Enforcement: Primary
Texas
Hand-Held Devices: Allowed
Bus Drivers: Banned When Students Present
Novice Restrictions: Intermediate License Holders
Enforcement: Primary
Utah
Hand-Held Devices: Banned
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: Secondary
Vermont
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Virginia
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: Intermediate License Holders
Enforcement: Secondary
Washington
Hand-Held Devices: Banned (As of July 2008) Text Message (As of 2008)
Bus Drivers: Banned
Novice Restrictions: None
Enforcement: Secondary
Washington, D.C.
Hand-Held Devices: Primary
Bus Drivers: Banned
Novice Restrictions: Learner's Permit Holders
Enforcement: Primary
West Virginia
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: Learner's Permit and Intermediate License Holders
Enforcement: Secondary
Wisconsin
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
Wyoming
Hand-Held Devices: Allowed
Bus Drivers: Allowed
Novice Restrictions: None
Enforcement: N/A
[Sources: Governor's Highway Safety Association and Insurance Institute for Highway Safety]