When I had a Palm Pilot, one of my favorite programs was ListPro.

http://www.iliumsoft.com/site/lp/listpro.php
http://www.geekzone.co.nz/content.asp?contentid=2282

It was a simple, easy to configure database.

Is there anything similar (or better!) for the Nokia 770?

I've considered writing one in Python, but I'm still getting up to speed there.