I did some searching around and found this one:

http://www.amazon.com/exec/obidos/tg...52053?v=glance

In case that link goes dead, it is an Alltrade tool #648796

I had seen some for as much as $90, so this seems like a bargain. Here is a site with a couple reviews of the tool:

http://www.toolreviews.info/B0000TML...oval_Tool.html