Does Microsoft offer anything in terms of online storage, something similar to Google Docs?
I'm thinking of just keeping a few essential files on the "cloud", so I'll need as little as 50MB.
Is there a Microsoft Office Online?
Windows Live Skydrive is probably what you're after. 25GB storage with a web-based interface. Slightly more than 50Mb than you want, but free to anybody with a hotmail/msn account.
The current name of the Microsoft online storage for consumers is OneDrive.
Regarding Office Online, the current name is Office 365. It's a subscription based service.
Windows Live Mesh
http://explore.live.com/windows-live-mesh-devices-help-center