What do you call those armadillo-like bugs?

It is rare for me to have the time and inspiration to take an idea that just pops into my head to full completion in a single day. I did today though with this little bug cluster! I've always sort of liked these peculiarly armored creatures.

Justin and I once got in a hot debate over their names. He thought they were called roly-polies and I thought they were called sow bugs. We tried to figure out who was right (because that is all important) by asking around and everyone seemed to have a different nickname for them. So far I've heard them called, sowbug, pillbug, potato bug, doodle bug, roly-poly, isopod and woodlouse! I'm sure there are different species being named here or something but if it is just one creature than I suspect it has the most dramatic ratio of names to body size.

My print (found here) is of a group of them clustered sweetly on scalloped paper with their nicknames (or misnomers) beside them.