Worm

It's probably hard to say just like that, but methinks this would be a caterpillar (you know, the larva that grows into a butterfly), not a worm. Nice critter, either way :)

Not hard to say, Mach... you are absolutely right, it is a larva (caterpillar) not a worm. It is a little harder to say what it is going to be when it grows up, butterfly, moth, or even beetle (although it looks like one of the first two). I'm going to make a wild guess at moth, perhaps one of the hawk moths. And I agree: nice critter indeed :)