I’m just testing GlideOS. It apparently offers you 10GB of storage free, it’s possible to create documents & presentations, to email them to people; to share the desktop with up to 5 users (for free).
It uses popups for the various tools; Firefox though, didn’t let me know it had blocked them, so I was a bit mystified until I tried IE. (It needs Flash 9+, though that wasn’t the problem for me) The “write” & “present” save files as .html; I was able to email them (it sets up an email account on creation), to set up a meeting with the presentation already loaded. The meeting feature seems fairly powerful – appears to offer 4 video streams, as well as text chat, sharing of files etc. There is also “The Cube”, which seems to be a video/music/bookmark sharing facility – though once I’d started a video & moved on to look at the bookmarks, I couldn’t shut it up! Oh, and you can create a website too. Probably more as well …
Seems quite powerful.