Keeping the forums spam free

With fairly popular forums we occasionally suffer from the odd spammer trying to sell his or her wares (usually mobile phones) but these types of posts are usually brought to our attention and removed, along with the user account in question, within just a few minutes. I'd like to take a moment to thank all of our members and moderators who play such an effective role in keeping the forums free from spam and other undesirable posts, without your help it would simply be impossible to keep the forums going and develop other areas of the site at the same time. Thank you!