Ladainian Tomlinson to the Jets

I don't really understand why the Jets picked up Ladanian Tomlinson (please do not call him LT as the only LT we refer to should only be Lawrence Tynes. Just kidding, we all know it should be Lawrence Taylor). Anyway, cutting THomas JOnes who just had the best season and then picking up a player who is on the decline doesnt seem to make much sense to me.