Something I found that could be really helpful from grathio.com.
“About once a month I see an article about some ambitious maker who’s project created an alarm at airport security. Most makers who travel with homemade electronics and other prototypes have a fear that their innocuous project wil catapult them to the front page as a threat to national security. While these news reports make up a good list of how to travel with bespoke electronics, but what I really want to collect is information on how to avoid getting into these situations to begin with.”