There are several DIY spray foam rigs on Ebay now. Here one I'm looking at:
SPRAY FOAM INSULATION EQUIPMENT DO IT YOURSELF PACKAGE - eBay (item 180622023774 end time Feb-12-11 14:51:54 PST)
For the difference in price of the Tiger/Handy foam kits versus buying this equipment plus 55 gallon drums of foam means I can pay for the rig and have foam left over.
Does anyone have experience with this or similar equipment?