It might be too late for this to be an option, as the Padres have reportedly agreed to trade Jake Peavy to the White Sox. However, the trade has not gone through yet as Peavy has a no-trade clause, and has not approved the deal yet. He has made it clear in the past that he'd be willing to waive the no-trade so that the Padres could deal him, but he's also stated his preference to go to another National League team so that he can hit.
If I'm Ruben Amaro Jr., i'm on the phone with San Diego until the trade goes through. I don't know how well the Phillies and Padres match up, though. San Diego would reportedly get 4 pitchers in the deal, including Clayton Richard, who has pitched in the rotation and bullpen for Chicago this year; Aaron Poreda, a AA pitcher who was Chiacgo's first round pick in 2007, and one or two other pitchers.
The Phillies can make a comparable offer as far as Richard and Poreda go by offering J.A. Happ and Carlos Carrasco. However, they might be hard-pressed to match the other pitchers involved (at this point unnamed). Kyle Drabek has pitched well since coming back from Tommy John surgery, and was recently promoted to Williamsport, but is still several years away from the major league level. The only other Phillies minor-league pitcher ranked in their Top-10 prospects (according to Baseball America) is Jason Knapp, the Fightin's second-round pick in the 2008 draft, who is currently at Single-A Lakewood.
For this to work, the Phillies would HAVE to trade Carrasco, which is something that they haven't been willing to do in the past. He's gotten off to a rough start this year after getting promoted to AAA Lehigh Valley, but they still love him as a prospect. It also will be a test to see how much of Pat Gillick's teachings have sunk into Amaro, in this case Gillick's dislike for long-term contracts for pitchers, and no-trade clauses. At this point, Peavy still has 2 and 1/2 years on his current contract.
I'd love to see them try to make this trade, as the rotation has been killing them this year, and putting Peavy and Hamels 1-2 at the top of the rotation could be killer once you get to the playoffs. It just might be too late.