ANONYMOUS Looks pretty good, I wouldn't mind the ability to add units to the depth and temperature, but I guess they're really not necessary.
The one feature that I would really love would be some iSync integration. Being able to store a copy of your log book online would really make me feel better about keeping something so important on my computer. If iSync support was added, it might be nice to have registration information included in the sync so if I was away from home I could just download the software, add my dives, and resync.
(Version 1.0.1)