I've read that it's possible to share information between iPhone applications using the Addressbook. In fact, TextExpander Touch seems to be able to do just this by looking at their SDK how-to:
http://www.freshblocks.com/tutorials/how-to-add-textexpander-touch-sdk-to-iphone-apps/
Can anyone provide a concrete example of how this is achieved? I've read that it involves creating a 'dummy' contact - but I don't see any such dummy contacts on my phone.