I'm lucky enough to live in the Denver area that has one of the top 25 JUGs in the world. Technically, I suppose that makes it one of the top 25 in the universe. Java User Groups are a great way to get exposed to what's happening in your community. I know it's easy to say that you just don't have time for yet another meeting, but think about the benefits of attending a JUG meeting before writing it off. JUGs, no matter how big or small, are a great way to network as well as expand your knowledge and skills. I've met some really great contacts at the Denver JUG that I'm not sure I would have run into otherwise. I'm fortunate enough to get invited to speak at various JUGs around the country, and continue to be amazed at the volunteer participation level and high quality of technological know-how at these groups
JUGs also make it quick and easy to keep up on new and interesting technologies. There are usually monthly meetings that provide presentations on various Java related issues. I'm doing a presentation for the Denver JUG tomorrow on the upcoming J2EE 1.4 Web Foundation technologies. This will give people a heads up on what's coming down the pike for JSP 2.0 and Servlets 2.4. Other topics that we've seen on the Denver calendar include Mike Clark talking about Bitter EJB, Ben Sullins talking about JMX, and an upcoming presentation by Grady Booch. Check out the local listings for a JUG near you and see what types of things you can learn. I'm sure there is something that will catch your attention. At the very least, you'll have a new place to ask questions and provide answers for your peers.
As with anything else, if you don't have a JUG in your area yet, make it happen yourself. There is no reason why a couple of folks can't get together and start a group. You'll be surprised how fast the group will probably grow.