Well it looks like soon you will be able to go onto Facebook and order food.  A company called ChowNow is now working on an app that will allow restaurants to create a custom Facebook page where customers can order take our pickup. In the article it also states that they will be offering restaurants a wireless tablet that will receive the orders and will allow them to communicate back to the customer when the order is ready. ChowNow has raised over $3 million so far towards building this system.

If you are interested in this or perhaps only restaurant, you can read the full post here:

http://techcrunch.com/2013/01/16/chownow-raises-3m-to-provide-a-facebook-and-mobile-food-ordering-platform-for-restaurants/