Hold your iPhone “.com” button for a second
If you are running the new 2.0 firmware on your iPhone or iPod touch, you might not have noticed a new handy shortcut in Safari.
When you type in your address, hold down the “.com” button to get a selection of 3 other domain name endings: “.net,” “.edu,” and “.org.”
When you tap on any of the endings, it will be automatically inserted in the address bar.
via http://www.tuaw.com/2008/07/15/iphone-101-hold-your-com-button-for-a-second/