Im working on the exact same concept (it isnt ready for public launch yet). The major hurdle Ive run into is the legal side of things - it is illegal to "sell" any type of potentially hazardous food i.e. hot food from a home kitchen no matter what state. You can sell baked goods like cookies, jams, jellies and so on from a home kitchen from a handful of states though.

http://en.wikipedia.org/wiki/Potentially_Hazardous_Food