While I’ve been looking through these sites, they all seem to provide more or less the same set of features. Budget Management, Guest Lists, Checklists, Scrapbook, etc.

I actually think that there is much room for improvement among any/all of these tools. Some things I think should be implemented:

1) Tools that can interact together: If I book something, can’t the checklist item be checked off, and the proper entries inserted into my budget automatically? The tools should work together to make our lives easier.

2) Interactive “Day Of” planner: Seen lots of basic ones, but this is where a nice Web 2.0 whiz-bang feature would come in very handy!

3) Sync with my calendar/contacts: I would like to be able to synchronize calendar/contact data with other external systems.

If anyone else has other suggestions, please do share!