Very useful link for when you need to email something to yourself, but it is over the 10MB limit. Can upload data up to 100MB (free) and then simply go to the link you created at home - and download the data. Used this many times, even in the class when we could find a usb memory stick.
Upload and save/share students work through this site.
Can be useful if you have a daily blog with the students as they can all post solutions and learn from each other.