TaDaList is a great potential tool but it looks like it is just a "marketing" teaser for Basecamp (nothing wrong with the approach … pretty good idea in general).

But my 10 second spin has two big problems:

• Manually have to share every list and not a hierarchy of lists.
• Lists do not have a hierarchy structure (lists of lists of lists etc.)

The lack of these two features make it non-starters for me to use this seriously. I freely admit that I am picky.