Right now I use IsBot (by calorie) and that stops most bots before they get anywhere near registering. I also use Glowhost's Spam mod and that helps with links. I use the Q&A for all else and have had no problems yet, but then I don't have a lot of traffic to the site. I'm sure the bots will figure those stop-gaps out sometime and it would be good to have another, if not better, option.