See the rules for well-composed
group photographs for newsletters here

Page 2: Here are some more good group photographs
that work for most of these rules.

Here is an excellent group photo from Apple's User Group site with four people. Note that the tallet person is sitting, the shortest person in farthest away from the camera. All are focused on something other than the photographer.

A nice three-person photo shows people working. Note the triangular arrangement that makes the photo attractive.

A professional, 10-person photograph used by an advertising agency to illustrate a focus group article. Note the coordination of colors, which is often impossible in newsletters. However, the arrangement of the subjects makes for an uncommonly interesting, albeit casual, group photo.