I always recommend everyone install the Low Askimet Combo on their EE-powered sites that allow comments. It’s an absolutely essential tool in fighting off the hordes of spammers attacking blog comments across the Internet.
There’s now another option available in the War on Spam, Low NoSpam, but this time with a few more features.
Like the Akismet Combo, Low NoSpam will check comments to see if they’re considered to be spam by the chosen service, either Akismet or TypePad AntiSpam. It can optionally also check incoming trackbacks, gallery comments, forum posts and wiki articles. Caught (gallery) comments will be set to Closed for further moderation. Caught trackbacks, forum posts and wiki articles will be discarded, since these do not have a native moderating system in EE.
So, with the new combo you can choose between using Akismet (from the makers of WordPress) or TypePad AntiSpam (from Six Apart) and Low has expanded what types of comments are covered in the protection.
Make this a standard module on every EE project you develop.