Say you want to send somebody one of your full size images or any other long data string, but your email system balks at files longer than 1 (or 2 or 3...)MB. You can send Email files up to 1GB long from here:

http://www.yousendit.com/

The way it works is that the data (image) you send is posted to a web page and the email recipient is notified by regular email of the web page address so he can download it from there as a normal HTTP download without worrying about email constraints.