My 14 year old son and I just returned from traveling from Idaho to Houston to catch two baseball games (Dodgers v Astros). I have been a fan of the one-bag means of travel for some time and usually use a Tri-star for that purpose. Since we were dressing super casually and only spending one night, we chose to "extreme one-bag", my son using his school backpack and me, only the copilot. In the main compartment I packed a t-shirt, socks and change of underwear in a small tristar packing cube. This left room for an iPad and Sennheiser noise cancelling headphones. In the right front pocket was my Jawbone Jambox speaker and a laser pico projector. In the left front pocket were my keys and iPhone. The middle water bottle pocket contained my 3-3-1 bag. A couple of magazines in the back pocket. It was great not to worry about finding overhead bin space. We often mentioned that we didn't feel we were missing anything. In fact, I now wonder if I had ditched the entertainment apparatus, if I could have done it in a side-effect or a Scottyvest, or packed enough clothes for a two night trip in the co-pilot.
My wife made fun of me for this (saying she loves my purse) and I had to explain that it was just a stunt, but I would do it again in a heartbeat.