Looking at the new project I'm finding myself tempted to create the entire thing in Ajax-ish Nevow LivePage/Athena operations, basically just one page that reconfigures itself as the user adds/removes/modifies items. There's little need for it, it just makes a lot of neat little bells and whistles (nice-to-haves, not must-haves) possible.

I'm resisting the temptation for now. We'll just use regular posts and forms for most of it... though a couple of core pages will likely use the LivePage mechanism to improve the perceived speed of the system.