There are TONS of things to get a Chi.
Lapel Pins, Mugs, Chapter Guard, Letter shirt.
It all depends on how much you want to spend.
I go on eBaY alot and have gotten a ton of cool stuff (chi stuff) from there.
http://www.universitygraphix.com/lambdachialpha.html - That site has a hoodie I got for Christmas which is really awesome.
But there are a billion things. Rings, Dog Tags, Coins, Lapel Pins, Cufflinks, Flags...