Domain Shortcut Helps Type URLs in Your iPhone More Quickly

From lifehacker -

For iPhone/iPod touch users - There is an expansion to the .com keyboard shortcut for entering email addresses and non-.com URLs. In Mobile Safari, hold down the .com button for a second to see other domain options (i.e. .net, .edu, and .org). 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.

Source article here.