For those who use Ubuntu, Ubuntu One offers 2GB free secure online storage.
What makes this different from other personal data storage solutions is that it's integrated into the Ubuntu operating system, you can select Files, Folders, Browser Bookmarks and all your contats which can be automatically syncronised with your free online storage.
Say for example you were working on some documents, when you update them they're automatically updated on the Ubuntu One storage platform also.
Ubuntu One also has a web based interface meaning you can Upload/Download files without being on a Ubuntu computer.
Check it out: http://one.ubuntu.com/