Why would you consider commuting from EWR to IAH??? I assume you're with XJT or CAL, both of whom have a base in EWR. Living in base is sooo mush better than commuting. Commuting sucks any way you slice it, and EWR-IAH is probably one the worst you could attempt. Like the above poster said, occasionally a flight is open, but 90% of the time those flights are packed. Just get yourself based in Newark. Many people are always trying to get out of Newark so it should not be a problem.