While the purpose of user groups is technical in nature, members like getting together for social events too. People frequently continue chatting after the meeting ends over chicken wings and beer or coffee and donuts. During the summertime most user groups take a holiday. Others opt for a club barbeque or pool party instead of a regular meeting. We are indeed social animals.
Some groups exchange more than information with each other.
Last year I got a highly amusing CD-ROM game for twenty bucks and sold a tape drive I didn't need anymore. It's the ultimate in recycling because one man's legacy product is another man's upgrade. Any user group's greatest resource is their membership. The efforts of one person often benefit many. Sometimes you contribute, sometimes you benefit from anothers' contribution.