I've discovered several ways in which I already work with Application Integration in my job.
In a very simplistic sense-- I am currently trying to work out a solution to allow a client to have functionality with both existing XP Windows programs that are built into business applications she uses everyday, and Windows 2003 applications which are necessary for the new Microsoft SharePoint 2007 suite I am supposed to be setting her up to use. It's more complicated than it sounds and is involving alot of negiotiation with both my co-workers in the IS department and the clients on the business side.... all in a days work....