Greater Seabright Community Project Guided by a very small group of enthusiastic volunteers, this group has established a yahoo! group with a calendar of events, and an online database of neighborhood resources (skills, tools, etc.). A template of their database is here.
The City Repair Project A Portland-based group that has inspired creative neighborhood efforts in many cities. Learn more about them and read selections from their excellent City Repair Guidebook here.
Santa Cruz Neighbors The city-wide organization that links existing neighborhood associations. Site contains links to relevant city ordinances, tips for running meetings, sample neighborhood surveys and fliers, and more.