Yellow Caterpillar

The girls found a caterpillar out on the driveway, and of course had to bring it in! I've been searching online, but don't really have a good method to look it up. It's probably about 2 inches long, yellow, furry, with long black hairy spikes sticking out. Anyone have a clue or a good website to use to check it out?

UPDATE: Found it! I just Googled "caterpillar" and searched around until I found ours. It's the American Dagger Moth, or acronicta americana. The girls are reaaaaly hoping that it will make a cocoon and turn into a moth, but I'm wondering what the odds are of that actually happening in a jar. We did find out that it eats lots of different tree leaves, including maple, which we have in the front yard. We'll see what happens!