Any of you guys visit/are regulars over at Reddit? They do a huge secret santa every year, and have a site (www.redditgifts.com) that they use to handle all of this. You should contact them next year and see if they’ll let you run a secret santa through their site. They’d probably be open to it, as there’s a subreddit for throwers over there (www.reddit.com/r/throwers), and they do little exchanges for different subreddits all the time (Doctor who gift exchange, crafts exchange, etc) I’ve done 3 gift exchanges using their system in the past, and they’ve all gone really well!
I won’t participate in this one, as I don’t have enough feedback and I’ve already signed up for reddit’s secret santa this year, but I just wanted to pop in and give that suggestion