Hello Google Spreadsheet (tested and I love it, but I am not a very demanding spreadsheet user), but not the least hello Google Writely (still in Beta).
Admitted Writely (your online Word) has not been fully integrated into Google yet (and doesn’t have the google look either, but it is very Ajaxy), but it is amazing how well it works. You can actually mail your word doc to it and edit it online or create new documents from scratch. Perfect for CV’s and other documents you want to have available wherever you go.
It is also geared up for collaborative editing, and according to the website 50 people can edit it, at the same time. (they have to be in different sections of the document though to make this work). But being able to share documents like this, is a big step forward if you ask me.
Also on it’s way Google Disk, online storage and a Google like Powerpoint program.
Microsoft Office is going to have a hard time.