Smarter Technology has a list of 10 apps to help you with being "green." They vary in price from free to $5.99 and cover a range of different uses including iRecycle, a free app that can help you figure out where to dispose of , well, hard to dispose of things:
Don't know where to dispose of your old cell phone or that bottle of motor oil? iRecycle provides detailed information about local recycling centers—everything from directions to hours of operations. It even has listings for nearby green events to help you stay in the environmental loop.
This is a great app even if you don't consider yourself part of the green movement. Check out the rest of the appp list here.