I'm assuming you mean out and backs. I've been very interested in this myself as well since both CFIing and 135ing I have been in my own bed everynight and been able to cook healthy stuff. The idea of 4 day trips eating airline and airport food scares the crap out of me.
There is one thread in this section I started called "out and backs" that has some airlines that have day trips. From what I understand, Colgan has almost entirely out and backs in the northeast and typical airline layovers out of Houston. There are a few other airlines that have out and back routes, but the majority of their routes layover kind of trips.