Well, Live Folders allows 50MB upload per file (1GB of storage total)
Its great for Forum type stuff, and sharing certain files with friends/family/everyone
It has permission groups (public, personal, contacts*)
All that is required of you is a Windows Live ID (Passport, or Hotmail account)
For permission groups, contacts that you allow must have a Live ID as well. Public files (ones that anyone can access) does not require any such account.
* You can select which contacts are allowed