If the Jets look to replace Kerry Rhodes internally, a lot of money will go on Eric Smith being the guy. I could see them going a bit outside the box and turning to Dwight Lowery to play free safety, though. I think he's got the tools to make a good one.
The knock on Lowery as a corner is that he isn't fast. Our own David Wyatt argues he doesn't have the range to play safety. Everybody here should know by now how much I respect David's opinion, but I'm not sure I agree in this case. Speed at safety is different from speed at corner. Lowery's biggest problem is a lack of fluidity when turning his hips in man coverage. He has pretty good lateral speed, which comes into play more as a safety. When he was drafted, the book on him was he was more skilled playing zone coverage, which would make him a good replacement for Rhodes since Kerry was asked to play a lot of Cover 1 deep. He's also better diagnosing plays in front of him than he is playing somebody in physical fashion right at the line.
The other thing working in his favor is his experience at the position. He wouldn't be a total blank slate and have to learn the nuances of the position from scratch. He played quite a bit of safety in college and was a real ballhawk. Starting 15 games at safety, he had 13 interceptions. I know the competition wasn't that great, but that's still pretty impressive.
He is only 5'11" and 198 pounds. Paired with Jim Leonhard, the Jets would probably have the smallest safety duo in the league. As we know, though, Leonhard plays much bigger than his frame. Lowery won't remind anybody of John Lynch, but he is a sound tackler and would probably be an upgrade over Kerry Rhodes against the run.
The more I think about it, the more I like the idea. Dwight could play a hybrid role like Antrel Rolle did with the Cardinals, lining up at safety and sliding to the nickel in passing downs. I'm not sure this would be my first choice, but I do think it could work pretty well. He could be a playmaker in centerfield.