I liked iGoogle's start page because Google's interface is familiar, simple, and not as advertisement "heavy" as others.
However, as far as online productivity tools ... Call me a curmudgeon, but for me personally, it's easier to do paper post-its, to-do lists, and calendars than to invest the time in orienting myself to the online versions. Gotta tell you - there's also a certain satisfaction in checking off/throwing out paper lists of items that have been completed!
The countdown clocks were just creepy to me - sort of the whole Doomsday countdown sort of thing!
I looked at the about.com "Top 10" list of productivity tools. I have used TinyURL and really like that. It's a keeper.
Glad I looked at this "Thang," but I think I'm okay right now with my present organizational strategies.