Shortly

Shortly is an easy-to-use utility that lets you create short URLs (Bitlinks) with your iPhone or iPad using the Bitly service. You can copy these links to the clipboard for use in other iPhone applications. Once you've created your Bitlink and pressed the button to put it on the clipboard, you can launch another application, click anywhere you can enter text and select Paste — it's that simple!
Additionally you can track the click statistics for Bitlinks you create in the app, or Bitlinks you've shortened on the Bitly website with helpful charts and metadata. There is also a Bitlink lookup tool, so you can enter in a Bitlink you've found and see who created it, including the number of global clicks it has received this week.
The app requires a Bitly account to enable the URL shortening and tracking features. If you don't have an account, signing up is easy and free. Just click on the Account tab in the app and click the button to get a new account.
Auto Shorten feature: If you go into the Settings screen and turn this on, the Shortly app will look on the clipboard when it launches, and if it finds a valid URL there, it will automatically shorten it and place the Bitlihnk on the clipboard at the same time.