I'm going to wait for a while before I get my 32GB card. Prices will fall soon enough. I don't want to double the investment on my Evo by getting a 32GB card. I'm getting by with 8GB so far, and will move up to a 16GB when space becomes an issue.
As for where to look, I'd try androidcentral.com , geeks.com, amazon.com, and newegg.com.