A while ago we started on this project with some friends, a method to add tools to CraigsList. The first tool was an Auto-Responder. There were other auto-responders on the market (but those cost money) and we needed the tool so there it is.
We’ve recently made an addition to the CraigsWish utilities in the form a response-filter that creates a database of respondents who answer a set of user-defined questions. Pretty simple, easy way to organise the mass of responses to CL posts. Plus it does a GeoIP lookup and give the ability to rank and annotate the respondents.