This is reviving an old discussion but the problem mentioned (neighborhood monitoring and security) is relevant for a lot of neighborhoods and worldwide. Coordinated action taken by the HOA or neighborhood watch will definitely help in such cases. I hope you found a solution and if so please share.
The TenM3 Internet service
http://www.tenm3.com will be a good DIY solution for such situations - and very simple to use.
At each house (or location), only an IP camera with an Internet connection is needed and setup in the TenM3 account. As many or as few cameras as needed can be deployed. View, Share, Record is then all done over the Internet - so no DVR or other local equipment is needed. Recording can be 24x7x365 or just for the time periods of interest e.g. a specific 5 minute each day.
The neighbors can cooperate in keeping an eye on the neighborhood - from their work or home. Many people can simultaneously monitor each live feed. The live feeds can be shared with the neighborhood (via email) for this purpose. If needed, each Share can be a time-based share.
The Panasonic IP cameras (BL-C, BB-HCM series) are good for home use and widely available. Models with different price-features are available -- wired/wireless, indoor/outdoor, night vision etc. Prices range from $80 (entry-level) to $800 (full-featured). A few popular models are Panasonic BL-C1, BL-C131, BL-C140, BB-HCM527 and BB-HCM581.
The overall solution is inexpensive - one-time setup costs (buying the camera) and TenM3 usage costs (only when used)
A monitoring solution for a office, office-complex is below. Similar steps can be taken for the neighborhoods.
http://www.tenm3.com/blogs/?p=385
A few TenM3 live-feeds in use can be seen here
http://www.tenm3.com/blogs/?p=522
and sample recordings here
http://www.tenm3.com/blogs/?p=243