This is moot now, since Roy Oswalt has confirmed through agent Bob Garber that he'll stay in shape on his own and look to join a contender midseason, but over at FanGraphs, Dave Cameron tried to come up with an innovative solution by inventing the must-trade clause:
So, here’s a thought – maybe Oswalt and his agent should invent the anti-no-trade clause.
1. The base salary is $5 million, paid out evenly over the course of the season.
2. There’s a $3-$5 million signing bonus, payable September 1st.
3. Oswalt specifies a list of teams to which he will accept a trade before the season begins.
4. If Oswalt is not traded to one of those teams by August 1st, he has the right to opt out of the contract and become a free agent.
The idea being that Roy Oswalt could help himself more by pitching against real batters in real games for the first few months than by working out independently. It would be kind of awkward for the signing team, since everyone would know that Oswalt is a goner, but there are worse things than having Roy Oswalt around for a little while.
Anyway. I'm sure Cameron's idea has flaws. Beyond that, it's just not going to happen. But there's no denying the creativity.