PinaxCon is a working demo of Symposion and the Symposion Starter Project. It usually lives at https://github.com/pinax/PinaxCon
This is a fork of PinaxCon to demonstrate Registrasion, a registration package that works well with Symposion. You can find Registrasion at https://github.com/chrisjrn/registrasion
Registrasion has relaively complete docs at http://registrasion.readthedocs.org
This project provides some starter templates for much of the functionality of Registrasion, as well as demos of how to make payments and enter user profiles.
If you care to, you can also use this project as a starting point for your own Registrasion-based site.