These are all some of Tim's favourite things from Gathering for Gardner, G4G, www.gathering4gardner.org/, an amazing get together that happens every 2 years in Atlanta, Georgia.
It started as a way of paying tribute to Martin Gardner, who wrote a very popular column about recreational mathematics for Scientific American for over 30 years! He attended some of the earlier events, although he is sadly no longer alive.
The mission statement says 'The Gathering 4 Gardner (G4G) Foundation stimulates curiosity and the playful exchange of ideas and critical thinking in recreational math, magic, science, literature, and puzzles to preserve the legacy of writer and polymath Martin Gardner.'
Part of the event, which runs over a number of days, is the puzzle exchange; you have to take an original item with you - but there have to be 300 copies that you can hand out! Other people bring their item and hand it out, so you take out 300 identical items (your exchange) and come back with maybe 100 different physical items, and then later on when the book of the event comes out, you will be able to see the contribution of people who wrote an article as their contribution.
This video shows some of Tim's favourite things that he has received over many years of attending G4G. He is very much looking forward to G4G14, which is in the Spring of 2020.