Sure, you could use the widely available Text Expander app. However, one benefit of iOS “Shortcuts” – what Apple calls its expansion system is that it is system wide. This lets you use snippets, er shortcuts anywhere on your iOS 5 device.
Turn on Shortcuts in Settings > General > Keyboards. Click the “Add New Shortcut” button to add a snippet.
Type in the full phrase you want your iOS device to type, and the shortcut (the abbreviation).
When you want to use the shortcut, type in the abbreviation and a space, and the full text is pasted in.
Make short work of emails:
You can create shortcuts for email signatures or for whatever text you find yourself repeatedly typing.