Look at these:

http://www.metalitek.com/latex.html
http://www.createamate.com/default.aspx
http://makeyourowndildo.com/makeadildo.html
http://www.liquid-latex.com/prod08.htm

One of them had a way of putting a vibrating egg inside. I've read that all of the materials in the kits can be found at crafts stores for a LOT less...just G-rated wrappings