Since I already have a google account, it made sense to take a look at Google Docs. This is something we're already using at work, so I was interested to learn more about it.
I think it's a great idea, and it seems so obvious it's hard to believe it hasn't already been done. My normal method for transferring documents between computers is to send them to myself as an email attachment. Google dos just cuts a step out of this process and makes everything more convenient. I love it!
The only potential downside I see is the loss of an internet connection destroying your work when you try to save. However, the fact that Google will autosave it every few minutes helps with that as well.