As a side note, newer plains (787 dreamliner especially) are built to have higher air pressure, closer to that at ground level (6000 feet instead of the normal 8000), which results in less of a change over the course of the flight.
Yes. Bring a sippy cup on the flight and have the baby take small sips (if possible) while the flight is gaining altitude. This act will minimize the pressure in the baby's ears. Also, bring toys the baby hasn't played with in a while or buy new toys for the trip. The toys will keep the baby occupied.