Other than Craig's thoughts about finding a job, that's pretty much the only reason I can think of too. I guess it just has to be something that interests you. Like belonging to a club or something.

>I think, it's giving you the opportunity to meet your colleagues, which is invaluable. I found two friends on User Group meetings in Boston and enjoyed time spent there. I wish there would be a user group here in NY.
>
>Last Thursday my colleague and I went to .NET meeting in downtown. It was a great experience for me as well.