I never thought twice about the default akismet spam filter that comes with WordPress. I just turned it on and forgot about it. I am certainly glad I did. This blog is only days old but already the spam comments folder is filling up.
It is a very simple process to turn it on. Go to your plug-ins page and turn it on. Then you will also need a wordpress account which you can get from wordpresss.com. you just need a username, not a full blog. After you sign up, they will send you an API Key which the aksimet filter is asking for. Just feed that in and you are all set!
You can then play with the settings if you want, and it will keep all the spam comments off your site and in a seperate folder so you can go through them and get rid of the ones you don’t want. Or you can just delete them all to save yourself some time, but it is interesting going through them.
With such an easy set-up, there is really no reason to not turn it on. Unless you like a bunch of useless comments that is.