Recall I recently made reference to a very cool mashup found at alertdude - this was in reference to a mashup tracking sexual predators. Well, it turns out I also recently received an update from the developer Matthew Dubiel and it turns out he's been up to some very cool things. A while back he created theaterdude, a national theater finder and mapper for the US. Then he thought about doing yard sales or maybe gas prices. But it eventually came to him that instead of making site after site after site, it would be wiser to group them all. Enter the latest development found at the alertdude groups. Imagine being able to create a named group where you can invite friends to post items in the mashup and build the group. Create a group of garage sales, a directory of professionals, personal ads, events, or ??? that's exactly what you can do at the new groups utility from alertdude. As a sample I created my GISuser Group - a directory of mapping professionals. Try it out. Simply add yourself by creating a quick user profile (email and pw) then add your company's information or calling card... way cool! See http://www.alertdude.com/groups/ and look for the GISuser Group. Maybe even create your own group. Once your group is created you can add a listing, post a picture, description, contact information etc... from the group application users can contact you or leave a message.