Hand saws are obviously less expensive than power saws, but some object to the amount of elbow grease required to get through a whole project using only a hand saw. On the other hand, the hand saw is a great form of exercise, provided you don't overdo it.
When using a hand saw, it's important to start with a few strokes that make a notch in the surface you need to cut. This will help hold your blade steady deeper into the cut. Use the length of the saw for the cut, not just a few teeth. Avoid pushing with the handsaw, and you'll get a smooth cut with little "binding" as you move through the wood. If you are using good technique and the saw refuses to cut straight, chances are your saw blade is dull and needs sharpening.