Building a community for your street was too easy. So build a community for your city instead. Most councils and governments fail spectacuarly at this, but you're going to succeed.
Like creating an online community for your street, you still need to find people who share your passion. Identify and begin building relationships with people from different areas, streets, businesses, political and community groups. Have a group of 10 people who you feel comfortable asking for help. In most cities, your friendship group should exceed this.
Now register your city on Ning. Bring your allies to create discussions on big issues, start groups for their areas/companies/groups ask them to bring their people in to the community.
Or, if you want a shortcut, talk about them. Talk about the streets people live in, then tell people who live on their street. Talk about a local coffee shop, then tell a member of staff. Talk about the work of a community group, and call the group to tell them they’re being talked about. Mix online forums with traditional offline communications. Ask these business to participate.
The key here is groups. Don't let one small group from one area dominate your community. Let them dominate their area – nothing more, nothing less. Your community is the sum of each of these groups.
What next? Challenge the newspaper. Interview key members of your city for your community. Better, get members to interview each other for their community groups. Go hyper-local. Call companies who send you junk mail, and sell them advertising opportunities on your community.
Get the local council involved. Create an “Ask my rep” thread. Demand the council spends an hour a week answering questions from your members. Invite their political rivals to also answer these questions. Sign sponsors for these debates, and your top community columnists.
Celebrate your community’s achievements over the traditional way of doing things. Write your shared history together. Arrange meetings for community members. In no time you should have a high number of active city members.