Or, technically, high above it.

Back in a few days with more stuff. Stay tuned..
Looking at the December 2007 issue of Vanity Fair, I was pleased to see that Annie Leibovitz didn't shrink from the challenge of shooting a giant group photo of the American patrons of the Tate Modern Museum. Way to go, Annie! You're gonna do just fine in this biz.
Putting people at different heights and in different positions can add a great deal of texture to a group photo. I joke with my clients that I try very hard to NOT make their photos look like "the debate team in the high school yearbook." They laugh because it's pretty much an archetype: a bunch of people lined up in a row looking awkward. Sometimes it's two rows. Doesn't matter. You don't get any sense from that image of who's naughty and who's nice, who the funny guy is and which girl is most likely to succeed.
Photography is inherently a two-dimensional medium. Whether you're looking at a print on a wall, or illuminated pixels on your computer screen, you're basically seeing a flat surface. Why magnify that limitation by creating a police lineup? In the image above, even though the subjects are all basically standing in one plane, I've created a pleasing front-to-back sense of depth by moving off-axis. Do all that you can to spread out your action and take the viewer's eye from place to place in the image. You have to watch your depth of field if you spread them out too much, but if you're working with the light you can pull it off.
If you can get your peoples' minds off the fact that they are your subjects and distract them in to think they're having fun, you're going to get a better picture. One very natural and easy way to do this is to have them walk around. I have the whole group walk maybe 50-60 yards away from me, and then turn around and all come back. I tell them to talk to each other, joke around, shake off any tension they have. Shooting with my 70-200mm zoom, I can generally fill up the frame with the crowd and widen out as they get closer to me. After a few attempts at this technique, you'll figure out some ways to get people moving in a more coordinated fashion. As your people loosen up a bit, they will be more likely to look pleasant and comfortable if you do have to tell them to look up at you for a second. And they'll look up at you because you have elected to; 
You'll see in most of these images that old Sol is striking everyone on the back of the head and shoulders. That's a great way to separate everyone out from the background. If you need, you can generally get away with just a bit of fill light on their faces from a couple of small strobes. Perhaps even more helpful, it avoids the issue of having a viewfinder-full of squinting, uncomfortable people staring up at the brightest part of the sky. If they don't have to squint, they can smile. And they'll feel better about you, because you haven't blinded them. So don't be afraid to shoot in to the sun, or at least get it off to the side.

I have my own frequently-used curves preset, called "tiny bit more contrast, eh?"
Notre Dame de Paris. Duh.
Sinners suffering on a cathedral wall in Angoulême




