TJ Creamer spent six glorious months on the ISS, as a flight engineer and science officer for Expedition 22/23 (Dec 2009 - June 2010).
Now back on Earth, he splits his time between JSC and MSFC. While in Houston, he engages with a special focus on networking and all things I/T on Station. When he is in Huntsville, he serves as a certified Payload Operations Director, the only astronaut with this qualification.
But hey! The most important part? TJ was the first astronaut to live tweet from space:
"Hello Twitterverse! We r now LIVE tweeting from the International Space Station -- the 1st live tweet from Space! :) More soon, send your ?s"
For more info on TJ: