What kind of technology and role interests you?
Pure technology companies tend to center around oil and gas, aerospace, and medical domains and have both software and hardware components. HP still has a sizable campus on the northwest side.
That said, there are firms like AIG, Insperity, Fiserv, and PROS that have a large software contingent in order to deliver their services.
Also keep in mind that the Houston area is very large so where you live relative to the company will matter if you want to minimize the time spent commuting.