Dropbox

Sometimes you come across software that is just so useful, you wonder why didn't think of it and code it already. I have that feeling with dropbox. Install it on your home machine, your machine at work, the machine at your parents house and the tool will create a special folder; your dropbox. When you put a file into the dropbox, it will be synchronised to the web and all your other machines will also receive the file. Perfect! No more emailing files to yourself from your work email to your home address, no fiddling around with USB sticks.

I've been using it since public beta and I have to say it has become an important part of toolkit. You get 2Gb of space online to fill with your files and you can shared certain folders with friends. There is even a web interface.