Yep, I used Americart.com for a long time on an e-commerce site of mine, until the volume warranted going with a solution that has realtime processing. At that point I went with a Yahoo! store, which was easy to get set up.
MM
BTW, in addition to Amazon and Barnes and Nobles, I was just informed that the book is now available on WHSmith in the UK now (Ebooks only at this point) at:
The more the merrier.
Regards.