If you have a planned trade then yes exchange phone numbers! It can be hard to find people once you are there so send a text once you get there and pick a place to meet. If you dont have a planned trade just go up to people and ask if they or someone they know wants to trade. It can be embarrassing at first but youll get used to it! For every one person that doesnt want to trade there are 2 people who do! Have fun!
If you have extras and want to help show your support for our Japan cheer community and raise funds for the Japanese Red Cross - it's our first Global Cheer & Dance World Unity Project - Check out the shirt, bow and pin donation event at Worlds here... http://www.facebook.com/event.php?eid=141094255958654 - there are 4 separate days & times!
I know you're looking to trade, but it's very possible there may be some people all set to switch up at these events!!! More at http://www.cheerforacause.org.
haha this is a great question...my daughter trades and it just cracks me up, we will be walking around and someone will come up and say...are you trading, and she whips open her backpack and shows what she has, makes a trade and away we go .....but I always wonder how do people know to ask?...is there some kind of secret signal? its too funny.