A few years back I saw a post about a new company that was releasing trackables into the wild on their own and not inside geocaches and asking cachers to race to get them. Participants in the game would find a small metal coin with an activation code on it. The first person to find it (you could sign up for publications in your area) would take it with them and could claim it online. Then an actual "legit" geocoin that could be tracked on the geocaching.com website would be mailed to you (but you had to cover the postage).
I admit I scoffed at first, it seemed like a gimmick and I didn't expect it to take off. Several rounds (games) later and it's still going strong though. I've even picked up some tags in the Kansas City area and along the Eastern seaboard when I was on vacation. Apparently the folks out that way were not paying very close attention as some had been published more than a month. It was only after I got home and tried to activate them that I discovered it's one per person per game. Luckily I know a lot of deserving folks and happily shared them with my friends.
The latest theme pits two teams of spies against each other, RedHot or IceCold. By ordering a hider package you can get little briefcases of your teams that will be released somewhere in the wild for others to find. Additionally it comes with a larger case and a full size coin shaped like a spy that is handcuffed to the briefcase, very clever. It's a pretty nifty idea and naturally I chose the IceCold team. I know my friend Patrick of the Travelling Armadillos also plays and got one of each. I intend to put them in places I can't normally get caches published since they are temporary and don't go through a review process. The games goes live on 8/6/21, I'll be excited to see how long they last!