The iPad on Group Sale (demo)
syncfu.com
This is the autotrigger url:
http://www.syncfu.com/ipad.html#dosyncfu
syncfu.com
http://www.syncfu.com/ipad.html#dosyncfu
Could work. I really like the Groupon.com model though, where the price is specified, but it only activates after a certain number of people agree to buy.
Groupon and buywithme are cool, but centralization, just because of the purchasing model is not right iMHO. It would be much better that you have the option at the website of purchase, whether to buy now for the full price, or get in the group to buy later for a lower price. It's segmentation of the market.