I second the comment on Global Entry. It costs some money up front (per passenger) and time for a background check but if you are from the US and travel to other countries, your return to the US will be much faster. I have in both Miami and Houston cleared customs, picked up my bags, rechecked them, and cleared domestic security for my next flight in under an hour. Of course, if anything comes up (e.g. slow baggage, backed up TSA, etc.) you will need more time.