This is for a prototype project for local nonprofits dealing with feral cats. The idea is to involve grassroots neighborhood groups who will sign up for specific blocks of a neighborhood to survey, receive their kit, collect data, then have someone submit the data to the site. It will need to have tiered accessibility, with a limited number of people having full access, more that are able to input survey data, and the public who would be able to sign up for parts of specific neighborhoods to survey, but not be able to see survey results unless it's on a very general level.
I'm looking into mapping applications, with Google API being the most recent suggestion. I haven't had time yet to determine if this will customize appropriately for the data. Information bubbles won't be enough, the map itself will need to be able to be colored or somehow flagged to indicate sections of neighborhoods. All of this will need to be incorporated, with the public able to sign up for the survey of one or more blocks of the neighborhoods. Someone would then have to respond and provide them with the survey materials. This will probably end up with two separate maps, one with the detailed data and the other with the neighborhoods color-coded, surveyed, signed up and needing a surveyor.
I'm thinking this through as I type, so I realize I'm probably telling you more (and less) than you need to make suggestions. I am thinking that because of the proprietary issues they would probably want it to be within their own site rather than on a networking site that might have some claim to the content. That said, with the low development costs, I'm not sure if it will be possible to avoid being hosted on a third party network.



Comments
sounds ambitious
What you outline above sounds like a fairly ambitious application, that integrates a variety of functionality. One layer of that functionality might be the presentation of data on maps, for which the Google mapping API might be the right choice.
If I were going to attempt such a project, I would develop it on Drupal, but there are a wide variety of other web application platforms/toolkits that would serve as well. The choice, in the end, would probably be driven some by your requirements, and some by the preferences of the developers tasked with building and maintaining the application.
Given the complexity you outline, I don't know a simple solution that would not require some fairly technical development, as well as ongoing maintenance, both of which would require substantial resources to do right.