definitely this - I've done this a ton on Drupal/Wordpress also the "confirm I am not a spammer" checkbox does seem to cut down on submissions considerably. IM

definitely this - I've done this a ton on Drupal/Wordpress also the "confirm I am not a spammer" checkbox does seem to cut down on submissions considerably. IMO, a losing battle no matter what. A certain amount of spam is always going to get through. The real challenge is to do this without compromising your UX.