Chances are you wouldn't be able to set up an ad-hoc WiFi Intranet as most likely your neighbors are using completely different and incompatible router models, which probably don't have the facility to provide wireless bridging functionality.

http://compnetworking.about.com/cs/wirelessproducts/f/apbridgingmode.htm

Typically you would need to be using the same router manufacturer which have the a wireless bridging facility.

To bridge the individual networks wirelessly (assumming you can get the basic network working) requires some network design skills and agreements to cater for everyones requirements and to provide intranet communications requires some knowledge in setting up dedicated intranet email, webpage and DNS servers to share information on the local Intranet.

Typically a wireless bridge setup configuration is shown here;

http://www.draytek.com/user/SupportAppnotesDetail.php?ID=117

Then there is the issue of security.