How did the Jets get a third? Lamont Jordan? Maybe it says so in the article but I didn't read it.
For those who don't know, the quick and dirty explanation is that if a team loses more free agents than they sign, they are in the running for some compensatory picks. The greater a player is and how significant they are to their new team determines what round pick you get (earliest being a third at the end of the round).
For instance, I am pretty sure that the Colts may have gotten one next year for Edge, Thornton, Vanderjagt, and the DT they lost. However, they signed Adam Viniatieri so that bears weight on it too. Most likely, they get a fourth round pick or so.