At the International Puzzle Party which is held every year there is a day that about 80 or 100 puzzlers exchange a puzzle with each other. This is a summary of Oskar's exchanges over the years.

Puzzles
Ring Bracelet
Eight Track
Bram's Magic
Star Beams, Fold-A-Cube
Hurly Burly
Washington DC

Cold Fusion, Holistic Ring, Knobbly Box,
Hyperboloid six-(or seven)-piece burr

Spiral Burr
Minimal Twist
Next Floor, Tri Gears, Stellated Stasis
Coin Maze, Candy Wrapper, Daily Puzzle,
Feed the Cat, Snakes in a Plane
Writers Block, Aussie Zoo, Cross Keys Maze,
Rotten Apple
Pack your Gear, EGG centric, Boston Subway,
Moby Maze, Fragile Fractominoes.
Transmission, Free Willy, Gear Up,
Oskar's Almost Cube, Optical Delusion.
Heptagram, Cube Peels, Box of Swords,
Monkey Business, Moon Rock
Four D FourD, Mysterians, 15 Holes of Golf
Pathfinder, Sun Flower, Bronco, GGG or 1,5 Horses,
Driving out of Belgium, Big Wheel
Rising Sun
Rising Sun, Oskar Blocks
Hysteresis Key, Buffalo Nickel
Total Eclips
Keymaze
Keymaze
Thumbler
Thumbler
Knot Cube
Knot Cube
Electro Maze
Telephone Cord
Polariser
Fringe Slides
Origami Puzzles
Puzzle France