[UPHPU] Account manager/shopping cart

[Ash]

Are there any good open source account manager/shopping cart projects 
out there? I just need a program that can register a new user, remember 
him next time (after a log in) and remember their order from last time. 
I'll need to keep track of their billing address, but not credit card 
info. I'll need to keep track of their past orders. Also, the ability to 
edit their user info and add a new order. Also keep a few user defined 
fields. Php/mysql is fine.

I hate to re-invent the wheel, so any "build it yourself" replies will 
be burned with ritualistic fire.

Ash