Google Spreadsheets

Google is about to introduce Spreadsheets: Google Spreadsheets - Sneak Peek.

That's all great, guys, and I hear people even go as far as to say that combined with Writely it renders MS Office obsolete. But personally I am not so optimistic. How do you work/access your documents in the offline mode which happens oh so often at the times when you need those documents the most? We need some kind of hybrid to really solve the problem. And I wonder who is going to be the first to implement a sensible solution combining the best of both worlds. Microsoft?