Caltrans took pictures of all the state routes. You'll prolly want a county map if you're not familiar with California county lines, and if you poke around on the java applet, you can get an idea of what the different state routes look like if you were to travel them. It was amusing seeing State Route 273 from my laptop. :)
Check it out.
Speaking of other cool things from Caltrans, these are all the webcameras in Caltrans District 2, which is basically northeastern California. I live near the Deschutes and Riverside Ave exits, but you're not going to see my house from there.
It's still pretty cool.