I would *love* to be able to use the iPhone to interview people for podcasts, or to record phone conversations, for the same purpose. Unfortunately, the current iPhone development toolkit released by Apple does not allow developers to add recordings to the music playlist, or to sync in any way with iTunes, or with the Mac. So, the developers have been forced to make the user use *email* in order to have access to their recordings in their computer. A very awkward solution.
Until Apple provides a way for the developers to do syncing, these types of apps are going to have rather limited usage.