My biggest cross-over use of gear is on air flights. I fly about 90,000 miles per year, sometimes redeying out one night and back the next, taking 6 flights in 30 hours. So I like to travel light. Whatever business clothes I need are what they are, but otherwise:
"barefoot" shoes (for walking around town and exercise room if I'm otherwise wearing loafers).
are the most common items to come along.
I rarely check any bags for 1- or 2-night trips. Nor have a carry-on other than a book bag with clean undies, iPad, and any paper notes / plans / maps with me.
I bring my 2.4 ounce sea-to-summit daypack in case I bring back more stuff than I went out with. I wouldn't check it, but I"ll check my usual carry-on daypack having transferred that stuff to the UL sil-nylon version.
Around town on day hikes, I'm more likely to bring a puffy, shell, light, etc, because I've now get very light and compact ones.
I use my HX pots in the kitchen when I'm in a hurry to boil water or if I have many pots to bring to a boil. It is marked how much quicker a lightweight, HX pot boils a liter compared to a heavy, flat-bottomed kitchen pot, especially when they are used side-by-side.
I've tossed a canister stove and small pot in my fishing ice chest and been a popular guy when I brew hot coffee mid-morning on the ocean during a halibut-fishing trip.
It's not UL BP gear, but the single most useful item for my work and family travel are 15-foot-long, 1" wide, NRS rafting straps. Rated for 1,000 pounds. I use them to strap a regular duffle onto a roller duffle or luggage cart and wheel the larger load through the airport; to secure luggage unto the roof of a compact rental car until we get to our hotel; to compress stuff sacks within luggage; to secure closed ice chests or waxed-cardboard boxes of fish or caribou; and they can keep a damaged suitcase closed for transit. They'd also be more versatile than ny ties if you wanted to immobilize someone (if you're into that kind of thing).