As a function of being a crafty person and being lucky enough to work in the industry, I notice other crafters whenever I happen upon them; knitters in hospital waiting areas, patchwork bags over the shoulder as you walk down the street and hand made embellished clothing.
I must say though that I rarely notice people crafting at airports or on flights. I recently took a sewing needle in my coin purse along with a needle threader & Clover Pendant Thread Cutter onto a flight so I could sew missing buttons onto my coat which I badly needed on arrival in Melbourne. Apparently using a needle is ok however it is up to the discretion of the flight crew (I have been asked to put my needle away once when I was sewing a sashiko panel mid-flight). If anyone has more information to add to this, please let me know.
Returning from Melbourne I got in some crochet practise ahead of my 'learn to' class.
I find it strangely comforting to always have a portable project packed in a bag and ready to grab as I race out the door for long car trips, cricket or football games or potentialy time consuming events so I don't feel like I'm idle for too long.