The brainchild of a group of students and teachers from MIT, I-Neighbors offers a free and easy way for residents of a given community to exchange information (and maybe even bond). Search by zip code to see if anybody's already created a home page for your neighborhood; if not, you can create your own. It takes just a few minutes to register, and your profile can be as vague or specific as you like. Provide an email address to be included in the directory and to receive group emails. You can add events to the calendar, recommend cleaning ladies and handymen, upload photos, even contact elected officials (see GovLink). Of course, whether a neighborhood thrives or dies depends on the participation of its members. Is yours a ghost town? The site provides a ready-to-print flyer for posting at the gym or corner deli to help advertise the link and drum up interest.