My First Shopping Cart

Hello everyone, I need some guidance. After browsing through a few shopping carts, I've decided to write my own. I want to write one to satisfy the geek in me...just for the love of doing it. Plus, I want to add some additional features to it. Like, Wireless access, etc. Anyway, I'm looking for some direction on what's involve in a shopping cart. Mostly, I'm looking for a roadmap to make sure that I don't miss critical components (like security, multithread access, etc.) If you can, please send me a list of things that you think (or know) that a GOOD shopping cart should have. Include the small as well as the large items. I'm not asking that you write the code for me, only that you point me in the right direction. Any help would be greatly appreciated. Thanks in advance! -John __________John Monfort_________________ _+-----------------------------------+_ P E P I E D E S I G N S www.pepiedesigns.com "The world is waiting, are you ready?" -+___________________________________+-