Another factor leading to pucntures are underinflated tires. I have yet to have a puncture on my '07 Langster. I check my tire pressure on a regular basis, once a week, and make sure they're pumped up to 120 psi. To ride them at a lower psi, say, less than 90psi, would put the tubes at the risk of a pinch flat, or "snakebite".

You can check out new tires and tubes, but have the bike shop give a serious look at the wheels. There might be something out of the ordinary that is also causing the flats, like a spoke nipple head poking through the rimstrip (there should be a rimstrip), debris from and earlier flat still in the tire, an exposed wire bead sticking out of the tire, or simply riding around on underinflated tires.

Be sure to purchase a quality floorpump with a gauge so that you can always check the tire pressure as well. Topeak, Specialized, Silca, and Pedros all make quality floor pumps.