I joined writely – the online word processing application.
It is awesome. You can create/edit word docs online (with all the word features, specially spellcheck and formatting) and the share them with others, tag them, invite others to add stuff to your docs, blog them and it also maintains the revision history of docs.
For your info., Writely has recently been acquired by Google. And soon, Google will be launching it under Google services.
Currently Writely is in beta stage and you can join it only if you are invited to join. u can put comments here if you need an invitation and I will send you invitations without fail.
All Writely lacks are other office processor features like Excel and Powerpoint.
Google may like to acquire for iRows for Excel documents.