Representative Mike Pence (R-Ind.) is said to be mulling over the idea of running for president in 2012. He plans to announce his decision in January, according to Politico. Pence would face an uphill battle if he does decides to run.
For one thing, history is not on his side. Only one sitting member of the U.S. House of Representatives had been elected president, according to Wikipedia. Others have managed to make a splash within their own parties. Ron Paul's (R-TX) rankled the Republican establishment during his 2008 run for president. Dennis Kucinich (D-OH) heckled John Kerry all the way to the Democratic National Convention in Boston in 2004. In all likelihood, neither expected to win. Instead, each used the primary process to build a nationwide network of supporters and donors. Maybe that's why Kucinich likes to call himself "America's Congressman".
Whether or not Pence could duplicate that kind of success remains open to debate. If he does run, expect his campaign message to focused on fiscal conservancy. After all, this is they same guy who wants to create a Spending Limit Amendment to the U.S. Constitution.
Photo of Representative Mike Pence from his official congressional website