Bitly is a link shortening service that also helps you share, track, and analyze your links. Now includes "bundles" which can be public or private, to gather your links by categories you choose. A social network style feed of other people's bitly links can be added to your dashboard.
An iOS app is available for iPhone. Wordpress plugin and API are available. Site includes a sub-site about the API for developers here: dev.bitly.com