I really like the new Office Live Workspace concept. Not ground breaking, but very slick. Easy to use and pretty fast. Integrates with three of your apps (Word, Excel and PowerPoint). It’s still in Beta (isn’t everything these days?) but seems very solid on first usage. Easily share workspaces with your friends, customers and community links. It is similar to SkyDrive in use, but in a more structured way. Workspaces can be based on templates such as Event, School, Home or Study Group (and more).
Links to your Live ID and took me roughly 30 seconds to setup.
I’m not sure of the space restrictions, but the site indicates you can store/share 1000s of documents.