But here it is:
Cheap (think Dollar Tree) dog collars work really well as lugguge straps. We normally take a couple big (wheeled) suitcases and a couple carryon-sized suitcases. Unfortunately, the carryons don't have wheels. Last year, we used scarves/ bandanas to tie the carryons to the wheeled suitcase. That way we had less to carry. Our old, cheap dog collar works great. It has a snap type buckle, is small, and so far seems like it will work pretty well. Plus, its the added advantage of being able to more easily identify our luggage in baggage claim because it has a collar hanging from the handle.
Disclaimer: I haven't actually tried this on a trip, just around the house.