Hear me out on this one. Favre wants out of Green Bay. Green Bay would like Favre gone but wants something in return. Green Bay doesn't want to trade him to the Vikings (which is supposedly where he wants to go).
So what is precluding a team from trading for Favre and then spinning him right back to Minny? We have the cap space to absorb him for a day and then ship him right back out. We could probably net ourselves a 3rd round pick by expending a 4th round pick to get Favre here.
Now, there are potential problems: namely, getting Favre to agree to come here. A quick line to his agent should be able to clear that up.
We'd be effectively deciding not to deal with GB ever again because they would want nothing to do with us after we did something like this but it's a business and they should understand that.