A lazy observation: Pittsburgh and Baltimore are pretty similar in a lot of ways. They have two of the premiere NFL franchises going right now. They both have treated me to some really good food. I will say that the best dinner I ever had was in either Philadelphia (tapas) or Baltimore (crabhouse), and the best breakfast I ever had was in Pittsburgh (pancakes). They have two of the consensus best baseball parks in the world. They both also apparently only have enough karma to cover the areas of food, football, and stadia because both of their baseball teams stink.
The Pirates and the Orioles don't make very good trade partners. Neither team is past the turning point of the rebuilding cycle, so proposing a star-for-top-youngsters trade doesn't work. While the specific needs of each team seem to match up (the Orioles need run prevention, the Pirates need run scoring), the players available on either side don't solicit much enthusiasm for a deal.
So: The Orioles trade OF Nolan Reimold to Pittsburgh for LHP Jeff Locke
Nolan Reimold has had an unsteady career, but he does own a 108 OPS+ in the AL East despite the Orioles apparent public face to limit his playing time. Pirates outfielders (including the great Andrew McCutchen) totalled just a .326 wOBA in 2011, while Reimold clocked in at .341. He is pre-arbitration and should be in the prime of his playing days at age 28.
Jeff Locke is a left-handed starting pitcher who's next year in the major leagues will be his rookie season. He was ranked 8th among Pirates prospects before the 2011 season by Baseball-America, with the note that he could be the best player the Pirates received in the Nate McClouth trade. For what it's worth, he has a career minor league 3.85 ERA and 3.42 K/BB ratio. He'd almost certainly slide right into the starting rotation in Baltimore.
Is this a realistic trade proposal? I really have no idea. I'm scared of over-valuing Reimold and undervaluing Locke, and of failing to accurately suppose the mindset of the Pirates's front office. Are the Pirates really in a situation where they would be willing to surrender a quality pitching prospect for an improvement to their offense? Well...you tell me.