A recent BusinessWeek article (September 24, 2007) talked about the need for managers and companies to develop a little more sensitivity when they launch company team-building or social events.  In some cases, the events themselves cause their employees undue discomfort, and thus work against the event's intent.  Examples of events that may cause angst include: sporting contests like golf or bowling, "a day at the beach," even picnics involving employee families. 

While company social events can be good, the most important factor is understanding the composition of your workforce.  These events cannot be forced; and team building or morale strengthening certainly won't occur if part of the team feels uncomfortable.  If in doubt, let your team decide on events that would work-if any at all!

A major pitfall to consider, however, is that after-hours "team building" events can also be seen as one more trend in the blurring of the lines between the work/life balance.