If you're a fan of The World Ends With You (and who isn't?), you've got to check out the BokuButtons Etsy shop.
I can't decide which $1 pin I like more--the Joshua one below (buy it here) or this Neku one.
The BokuButtons folks also have pins featuring characters from the Pokemon and Zelda series. (They had a sickeningly cute Professor Layton pin on display yesterday, but it seems to be gone now. Drat!)