I like the idea of a battery grip for which ever camera I get. I got one for my film rebel camera and it makes it nicer to hold. Also makes it look more professional. But what all does the grip do? My film rebel grip is like $60 new and the 10d and 20d grips are like $200us new so im wondering what makes it worth it, or is it just because of demand, they figure people that are willing to spend $1000+ on a camera will spend a couple hundred more for the grip. My film rebels grip doesnt have a wheel or buttons on it, other than the shutter release, and the 10d/20d versions have the wheel, metering mode and something else buttons, but that cant tripple the cost. From the basic pictures that computers.com offers, it looks like it plugs into the 10d or 20d into a battery type hole, but I thought the batteries for these cameras were more like a square, about twice as wide as this hole in the camera. And then theres more than one type of battery that you can use in both the camera and grip. Is there a benefit of using the one over the other? Ive also heard of a no name version that is like 1/3 or less the price but is probably created by the same company that makes canon's. I would go to a camera store near by to check this out in person but none around here carry either of these cameras.