A local guy had one of these and swore by it.  Perfect for one nutters and blowouts.

http://www.qcsupply.com/50068-uncle-moe-pig-and-lamb-holder.html

I have used one like this.  It is ok, but I prefer Kurt cutting and me holding. :)

http://www.enasco.com/product/C05162N

Here is a homemade one.

http://thisnthat.4mg.com/photo2.html