Mollom - SPAM Blocking
I don't know why....but I'm still amazed at how much SPAM goes on out there...do these people not have a life?! Most of it is harmless (advertising) and do these people really think people pay attention to those annoying ads?
With my sites I program, you can easily block anonymous users from doing most things and also put the anonymous comments in an approval queue so they don't clutter up your site...but that still means a lot of SPAM to sift thru at some point.
The main problem is it sucks up bandwidth - even on 'simple' sites that are on inexpensive hosts, it eats up your valuable bandwidth. I've used CAPTCHA modules before but they only do a mediocre job. I tried out a rather new module for Drupal called Mollom and it works great! Simple to install and use. Very unobtrusive and very flexible to configure (easily allow trusted users to not be bothered by verification).
I installed it on one of my sites a couple of weeks ago and look at the stats:

I have no reason to believe the traffic was reduced for any other reason but for Mollom blocking out SPAM. I've noticed the over-all speed greatly improved on the site as well.
Another 'must-have' for any of my sites.

