mthsadthesupremecommanderor include their steam id somewhere in the purchaseLuckyLukeI don't know how "easy" it will be though sending the items to the right steam accounts.. Maybe they can use a list of emails, but I'm not so sure about that.
From what I understand the current method involves using the Steam Web API to grant the items to other people's accounts, although I certainly don't have experience with it.
You probably could do it if you had people sign in with a Steam account somewhere in the process.
Maybe it's possible to send out redeemable steam codes to all email adresses that bought / donated.
It's on the first page right now, woohoo!
http://steamcommunity.com/workshop/browse?appid=440&browsesort=trend