The 2012 Heavy Equipment Calendar features over 12,000 horsepower and 2,600 tons of filthy, beautiful professional-grade machinery. Get the calendar here if you're into heavy metal in the most literal way.
The calendar comes from the fine folks at the German Bauforum24 GmbH & Co. Just saying that makes me think of tunnel-boring machines and ore carriers getting dirty.
If you remember their past calendars, you can download them as wallpapers here.