It looks like everyone has Hunger Game fever. Check out a few Hunger Game themed things floating around the internet.
shirtwoot.com, a web company that hosts weekly shirt design contests and sells the top three winners, as well as other designer shirts has a Hunger Games themed shirt for $10 today. I believe the inspiration was from "Hungry, Hungry Hippos"
FAO Schwarz has gotten into the game. Though, I don't believe the backpack had the mockingjay or the #12 on it in the book... It's still cool.
The one thing I haven't really found yet is one specific clothing company selling Hunger Game themed threads. I know they are out there. I just need to do a little more digging.