Yeah, I've read nothing but bad reports of trying to thermoform standard clear styrene. It may be an option, but I figure it'd just be a waste of money.
Anyone know anything about acrylics? I've heard those do decently, possibly buy small sheets at a home improvement store. (I'm not looking for a complex shape, just a super-simple curve in a square sheet---it just has to be the exact right shape and size, and there's nothing I can find that's already the right curvature to cut down to size) Basically making a half-pipe/half-tube. About the size/curvature of a 2-liter bottle, but a bit bigger. If I could find a 3-liter bottle around here, that might be perfect.