I didn't realize IAH was actually in Houston. Though with the area size of the city, it's not a big surprize.

http://dept.houstonisd.org/ab/images2/CoHHISD.gif
http://www.houstonairportsystem.org/

And for only $269.20 you can fly roundtrip between the two airports (hmm - beats traffic?) But combine it with another flight, and EFD-IAH-XXX seems to be only $10-$12 more than IAH-XXX. So with a fully loaded RJ, they'd make a little less than $300...

I wonder what the peak 3-aiport service was in Chicago. (I know at the end there was just CGX-SPI service...)