How often you email the url's of the websites to your friends?
Say while you are browsing through Amazon, eBay you found an interesting book or gadget that you want to share with your friends, and these url's will be very very long (probably running into 2-3 lines). To avoid these url's running into more than 1 line the best way is to cut short the URL. Many websites provide us with this option like TinyURL , SnapURL, URLci, URLsaw ,...
For Mozilla lovers here are few Mozilla Addons.
No more long url's!