[support] Contact form anti-spam protection

I use the built in Drupal site wide contact form on a number of sites. It seems that spammers find the form and start to do their thing fairly quickly. Especially on our University web sites which have a lot of exposure.

I am looking for recommendations for anti-spam protection for the contact form. I have used the captcha module and the spam module in the past. Are those still the best approach or are there other options for best practice?

I have also signed up for an account on http://mollom.com/. Figured that may be another alternative, but haven't checked to see if the mollum module works for forms other than Drupal comments.

Thanks! Mark