Tons of options!
http://quiltville.blogspot.ca/2012/0...ine-cases.html
The other thing is that Dave McCallum -
http://www.featherweight221.com/fwrx/index.html - suggests using a lamp with a stable base and heating the inside. That's in keeping with a lot of the comments in the other link above. I can't remember the specifics of what he said (wattage and time) but if needed, I suppose I can bring myself to watch that portion of the DVD again...
This link has some good suggestions too:
http://artisanssquare.com/sg/index.php?topic=11086.0