In every Disney Park and the Market place there are pins and lanyards for sale. You start by buying a lanyard and a few pins. As you walk through the parks you can trade one of your pins for any staff members pin that you like. Certain pins are staff only issue so they are off limits (staf will normally explain that to guests). It's a fun activity for kids and adults alike. Liz used to be a pin nut but has resigned herself to just buy souveniers instead of doing the pin trading thing.
There are some really cool pins in the Parks that display certain locations, attractions, characters and celevrations occuring in the park.

