Dropbox is online storage for files, photos, music, and video. I've been toting around a flash drive containing all my novel files and information because I work off of too many different computers. I am constantly worried about it breaking or accidentally deleting something (like I did with a chapter in March *grrrr*) or loosing it or forgetting it at work or . . .
Dropbox takes care of all of that. You can work directly off of their servers (once you put your files there) or install dropbox on all of the computers you work on. Your files are automatically updated. A 30 day record is kept of all your changes and deletions in case you need to go back or you screwed up something. Like say, you accidentally deleted a chapter because the touch pad on your netbook is too sensitive *grrr*.
There is also a sharing feature, both public and private. Folks invited to private sharing can work on the shared files. Everyone with rights to that shared folder are able to see what changes have been made. This is great for group projects or criticing.
I've already loaded up my current data that I'm scared of loosing. I've been able to work off of the internet and not use my flash drive. You get 2g of free space and an extra 250mg for everyone you get to sign up.
Here is the link. Go check it out for yourself.