The purpose of a realtor sponsoring a neighborhood website is to build relationships. It will only be successful in doing this if the site has value in it, and its only a 'soft' sell of your services!
In addition, you realy need a mechanism to capture email addresses so you can communicate with folks regularly.
The solutions from
Non Stop Neighbors seem like they provide all this - high value add for residents, privacy (so residents have to register and you get email addresses), automated communications and so on to make life easy for the busy realtor - and designs that make it look like a neighborhood resource rather than a real estate resource. You should check them out.