You ever wanted to simply move one or more files like images or couple mp3s between workstation, laptop or mobile device, but don't really have dropbox or similar service configured?

For this purpose I've found myself using Gmail as intermediate stop. Just start a new message, upload some stuff as attachment and save the message as draft.

Open up Gmail on the other computer or device, download the attachments and delete the message. And like that, you've just used Gmail as ftp-server!

The only limitation to this method are google's attachment restrictions. In short, up to 25 megabytes and avoid dangerous file types like executables.