The pins from the battery and the Kellogg's pins are great traders since they're "free". (Have to buy the pack of batteries or buy 3 boxes of specially marked Kellogg's cereal.)
The best site to look up pins is pinpics---
www.pinpics.com
The best site for information about pin trading is
www.dizpins.com
Disney's pin trading website is
www.officialdisneypintrading.com
Sadly, yes there are sharks at DTD, the parks, and the resorts. There are even guppies. The children of the sharks who are told to get specific pins for them.
There are official disney pin trading nights at some of the resorts.
Thursday night is the All Star Sport resort food court from 7pm to 10pm
Friday night is Contemporary 4th floor from 7-10pm
1st Saturday of the month is Pop Century food court in the afternoon, don't remember the specific time.
Pin trading can be lots of fun...and addictive. My son started when he was in kindergarten and a couple years ago, my husband and I started collecting.