I personally have bought a small pocket sized book which has a wide list of different foods and their GI. I find it really helpful, and although I don't always find what I want in there, the list is still very extensive. I found it in my local bookshop - it cost me around £6-£7 (I imagine that's around $9 but not entirely sure). There are a lot of these little books coming out so I'm sure you'll be able to find one out there!
There's also this site - look to the left and click on 'GI Database'
Hope this helps!