Love the concept and look of it however I know companies before had issues integrating listings from craigslist because of their terms of service. Has this changed at all? If not it may be something to watch out for...read what happened to oodle: http://www.siliconvalleywatcher.com/mt/archives/2005/10/crai...
Just be careful, don't want to waste your time banking on something that is your only business model should it get taken away. Otherwise the app looks great and very useful!
Time can only time I guess?