Courtesy of Lifehacker comes this nice little tidbit:

An image of the iPhone

iPhone/iPod touch only: The iPhone has sported a .com keyboard shortcut for making quick work of URLs in Mobile Safari since it was released, but reader George points us to an expansion to this keyboard shortcut that can save tons of time for entering email addresses and non-.com URLs. First, in Mobile Safari, just hold down the .com button for a second to see other domain options (namely .net, .edu, and .org). Second, when the keyboard has the @ symbol but no .com key, you can hold the ‘.’ (period) key to get the same domain shortcuts—something that comes in especially handy when you’re manually entering email addresses or filling in login credentials in new apps. I’m not sure if this keyboard shortcut is an iPhone 2.0 feature or something that was added when hold-for-accents was added for international language support, but it’s definitely one to know. Thanks George!

(Via Lifehacker)