According to Kathleen O'Brien of the S-T, the Rangers are one of four clubs still in the running for Octavio Dotel, along with the Yanks, Mets and Indians.
Interestingly, O'Brien says that if the Rangers don't sign Dotel, any other bullpen additions would likely be added via trade, suggesting that the Rangers are pretty much done on the free agent pitching market, with the except of trying address getting another starting pitcher.
Which is probably just as well...there aren't a whole lot of other interesting candidates out there right now, and with Cordero, Leicester, Benoit, Wasdin, Castro, and Shouse, the bullpen is pretty close to full anyway.