The hybrid category initially was developed for a) replacing long irons and b) hitting trouble shots. The trend since 2005, however, has been to make hybrids more playable. If you look at the newer models, you'll find that they're a little bigger than the ones that were produced in previous years. Bigger gives you both a higher moment of inertia (for stability) and a deeper center of gravity (for height). However, watch out for hybrids that are so big that they play more like fairway woods. A good thing to keep in mind is that hybrids are meant to replace long irons, not fairway woods. That's how they're designed, and most golfers do better with them when they're fitted with iron shafts, not wood shafts.