Lots of us collect things to help us remember our travels. Some collect ticket stubs, some collect photos, and some of us just collect memories. I had one friend who collected baseball caps. I recall from the discussion What is your travel goal? that nuhusker likes to play military golf course and collect logo golf balls from each one.
As many on this forum know, I collect counties in the United States. More accurately, I collect postcards which I mail to myself from each county seat. Here's a picture of some I collected in August 2013 on a trip to Illinois & Wisconsin.
When I travel overseas, I usually end up with a handful of coins, and since I've always been fascinated by coins from around the world, I suppose I collect those as well.
So... What do you collect?
p.s. Marriott Rewards points is not an acceptable answer on this forum.