Type URLs and email addresses quicker in MobileSafari and Mail on the iPhone using shortcuts

To quicker type domain names with the iPhone keyboard in MobileSafari, press and hold down the ".com" button to have alternatives (".edu", ".org", ".net"). This even works country specific, so when you have the German keyboard enabled it will also offer ".de" (but will omit ":net") when pressing and holding down the ".com" button. 

This also works in Mail, if you press and hold down the "." button you will get the same choices as mentioned before with the ".com" button.

via Lifehacker