Coming Home to Roost

What's with these NFL players going back to their original teams? It seems like more than usual. First Jevon Kearse went back to the Titans, then today Trent Green returned to the Rams and Warrick Dunn came home to Tampa Bay. I guess it's that whole "if you love something let it go and see if it comes back" mentality. I totally butchered that saying, but you get the point.