If you're outdoors, if there's a slope or stairs you can try an arrangement like Michael has which wouldn't require a wide
angle. If not, put them in rows and try to arrange them in a bit of an arc instead of a line, so the people on the ends are
the same distance from your camera as the ones in the middle. If you put them in a line, stand too close and use wide
angle, the people on the ends will be noticeably farther from you than the ones in the center and will appear short in the
photo.