Review my startup: PadLister - Apartment Listings with Online Applications
padlister.com
padlister.com
An example of a listing page on the site: http://www.padlister.com/listings/6966.2-bedroom-2-bathroom-...
And an example of an online application form: https://www.padlister.com/rent_applications/new/6966
Crawling seems to be a poorly defined legal area, so doing it is wise: carve out your space while you can. But it would also seem wise to plan on getting denied to CL. You would not be the first nor the last.