When I was planning our first trip to Legoland I saw people talking about minifigure trading in the park. Similar to what Disney does with their pins, guest can bring Lego minifigures to trade with the team members in the park. Before we left we went through our bin and grabbed some of our duplicates for the girls to trade. Trading was super easy and does not cost anything extra. There were times we saw team members hanging around the parks holding a selection of figures to trade and on our last day we found the minifigure trading zone inside the Legoland coffee co. building.
Once inside the coffee shop you can read all about the story of the minifigures and have a chance to trade from this wall of choices. The was a team member there to help you get the character off the wall and replaced the open spot with one we had brought. My girls really had fun searching for the perfect new Lego character. This was also a good way to not have them all asking for new Lego sets while we were in the parks because they got to come home with a new toy.