In reply to tinytom:
You see I agee with the above that the grigri is not the best device for a beginner- but I completely diagree with the reasons they've provided.
Being taught to use a belay plate correctly is very important. Good technique comes with practise on these things and because they don't autolock people tend to treat them with much more care than a grigri. So you learn good practise.
I never use a plate any more (only ever grigri2) but it takes a lot more skill to smoothly and safely belay a leader with a grigri than with a plate for the following reasons:
1) Feeding out rope quickly for a critical clip is way harder with a grigri. You need to have slack in the system, you need to walk forward and you need to safely disable the mechanism (though petzl ask you not to do this). I personally take a big loop in my right hand and hold it then reach under and lock the mechanism shut with the minimum possible of one finger pad then feed out like a belay plate (should the climber fall my tip wont be strong enough to hold the mech closed).
2) It's much harder to control the speed of descent. There have been cases of people getting gripped to the lever and as the climber being lowered falls faster they grip tighter and open the mech further making the climber fall even faster. Not good.
3) Reliance on the lock. I've seen people take their hands completely off the rope while using a grigri. Not particularly wise
4) Easy for a beginner to thread the wrong way around. Really bad if you're top roping.
The list goes on.
In relatively experienced hands the GriGri is immense, but learn with a plate first.
Post edited at 16:22