I'm guessing Optimus Prime has just fired his lousy accountant, because even though he has a new movie about to come out, regular unwashed bastards like you and me can ride in Optimus Prime (in semi truck cab form) by simply hailing him through Uber. Well, so long as you're in one of these three cities.
Still, even 15 minutes nestled inside of Optimus Prime has got to be pretty fun, right? Uber is doing this as a tie-in for the Transformers 4 movie (titled Transformers 4: My Dinner With Optimus, if I recall). Uber has not commented on whether or not riders will be permitted to transform Optimus into his full robot form and then find the house of those assholes that teased you in high school and settle some serious hash.
It looks as though other Transformers, such as Bumblebee, will be available as well at a future date.
The cities are Dallas today, then Phoenix on the 19th, and then lovely Los Angeles on the 21st. If anyone is planning on quitting their job in any of those cities on those days, I can't think of a better way than to give your "take this job and shove it" speech, walk out of the building, and climb into Optimus Prime. You should arrange for some rubber to be laid as you leave with the driver beforehand.