Dropbox

Dropbox is a great file syncing tool. You can get it at this site.

Upon download, it will make a folder called "My Dropbox"

Simply put files in the folder to upload them to your dropbox account.

You will still have copies of the files on your computer, but other computers with Dropbox installed and registered for your account will immediately update the files as you update them on another computer. You can access your files from anywhere online and you can make changes to them on any computer you have registered.