I can think of at least four teams that would be relatively good fits for Pennington: Cleveland (presuming Mangini's departure), Minnesota (presuming Favre's departure), Carolina, and St. Louis. He'd be particularly useful on the latter two teams as a one-year starter holding down the fort while a rookie QB is groomed ala Chad Henne, while in Minnesota and Cleveland he would be more of a "win now" acquisition.
If he were interested in taking a backup job, then the question becomes which team wouldn't be interested in signing him. But in that case, he might as well stay in Miami.
My gut tells me that Pennington will stay here in Miami in some capacity. Slight chance he could become an assistant QB coach. Slighter chance he becomes the full-time QB coach, allowing David Lee to become the offensive coordinator.