Might work out to put in multiple, i.e. you can award Cookies for posts you like on the forums, and Pumpkin Pies for screenshots you like that are uploaded into the gallery.
I've seen plugins in the bukkit listing that allow web-connectivity in such a way that would let people spend the pies or cookies on the website to get items in-game. Who knows if they'll update quickly for 1.7.2, but it's a fun option to have for the future. (and anything that gets people involved on the website is a plus to help build/sustain the community)