Blogger-friend Julie posted a picture of a caterpillar with an ID request. I'd never seen anything like it, but I knew where I wanted to start my search:
the Discover Life Caterpillar Search Page. It doesn't have a particulaly large data base, but you can check the box for your mystery caterpillar's features, like stripes, spots, hair density, etc. and it will put the information together and give you a picture and a name for whatever comes close. It was enough to identify Julie's caterpillar as the larva of the Echo Moth. Pretty, and of course, we don't have them here.