For the last two years I've carried around a honeypot laptop every time I traveled. After my trip, I did forensic analysis on it to see if anyone tampered with it. I just wrote about the experience and methodology theintercept.com/2018/04/28/com…
I checked it in my luggage, which got searched by TSA at least 8 times, and left it unattended in many different hotel rooms, hoping someone would tamper with it. Unfortunately (or, fortunately?) I didn't catch any evil maid attacks. 
I had @debian installed on the laptop. Before each trip, I removed the hard disk and generated checksums of the data it contained. I also dump the BIOS firmware from the SPI flash chip. After each trip, I did the same, and compared.
Just checking for tampered hard disk and BIOS alone is a lot of work, and would be much more difficult on a computer I needed to actually use while I traveled. But there are so many other places where an attacker could have hidden something malicious that I didn't check.
It was a fun project. I learned a lot about hardware hacking, and I got to use cool free software BIOS tools like chipsec, UEFITool, and flashrom. Check out the article for technical details and methodology.
