Dropbox

I'm not an official distributor and don't get paid by them, but I do use Dropbox and really like it.  It behaves like a folder on your desktop, but is available on any computer you use on the internet.  It's much easier to use for file transfer than emailing things to yourself.

Here's a link to see what I'm talking about:  Dropbox.com

If you sign up, we both get 500MB free space.  You get the same deal for anyone you refer to Dropbox.

Along with Evernote, another software package I use in the cloud, this is a pretty nifty bit of cloudware.