Being a very budget conscious traveler, I've slept and crawled up at various airport and couchsurfing spots. From the modern and air-con ready international airport to central america's steel chairs and ghost airport.
One set that I always bring is a yoga mat and a square or rectangle scarf. The scarf is relatively easy to carry(on your neck) and yoga mat with its strapping or folded loosely in a carry-on bag.
The other one that I found VERY useful is a "Bagel" Universal Adapters+Extension Cord. Found this online and seemed to be a Singaporean startup, but being a size of a regular bagel, it's an extension cord for 5 plugs and 2 USB ports. This has won me many many friends both at the airport and at the host's house. Don't fight over plugs, share it with a bagel.