There's the good ole fake vagina made out of a latex glove and a towel... Theres an instructional video out on the web somewhere =P Takes practice to make a solid one and to not break the glove.
In the spirit of helping...
1. fold towel longwise and lay it out on a solid surface for a tight roll
2. place the latex glove with wrist hanging out about 1.5 inches on the folded edge, 3 inches from the end of the towel.
3. roll up the glove in the towel making tight, solid rolls
4. stretch the glove over the rolls...
5. lube the opening with whatever you have... lotion etc.
6. work away, can also roll up the the towelgina(lol) into something like a sleeping bag to make a more humpable object
