What type of camera do you have? P&S or DSLR? If you have a P&S you ncam just hold up the camera and take shots while hkeeping your eye on the road. You won't know what shots you get until later, but it's an idea.
Also, if you have it, you can use Photoshop to make the images interesting. I found this link
from DPS and this other one
about curves.