How can I use "Capslock" in iOS? On rare occasion I'll want to type a whole word in capital letters, but I can't get the iOS keyboard to "stick" it's shift down. In Android I can hold the Shift key and it'll stay in Shift until I hold it again.

How can I capslock/hold shift in iOS' keyboard? I'm on iOS 5.1
Double tap on shift to enable caps lock.

The shift button will turn fully blue to indicate caps lock is enabled:



A glow on the shift arrow after a single tap denotes a normal shift press that is removed after the next keystroke: