On-the-car wheel bearing puller?

[doubt at inwave.com (Nate Mellom)]

I've heard they exist, and I thought I remember someone on the list 
"renting" one out to listers.
My DS bearing is feeling nasty, but I don't really want to disrupt my 
alignment, or pay to have it done somewhere.
What say you?

Oh, and are Mk1 and Mk2 16v hubs interchangable?  I have my old hubs off 
my '81, I could swap one in temporarily, I think the bearings were okay...

Nate