I did see your suggestion. While it can probably help, that's another layer of plugin to monitor that can make the forum unstable. If you think about it though, how can spambots know the answer to 'Which company created the Nokia N900?' If they can answer that then they will be smart enough to skip answering that hidden field in that plug-in you are suggesting. That plug-in has been out for several years already and am almost sure they already know how to work around it.