Basicly this is the idea:
When a user creates an ad it should be posted on several (auction) sites at once.
Data has to be imported from (remote&upload) XML, RSS, CSV, TXT etc.
Also should have option to check for new ad's per day or week.
Ad's should also be able to be created manually.
The list of the websites it should be posted on is added. Also examle sites are included.
This also has to have a free-user(ad's with footer) and member system.
Preferable most things with AJAX like file/image upload.