The other option in the war on spam is to do as I do… ruthlessly moderate anything that looks suspect.

I just deleted at least 10 “valid looking” comments because they either used a keyword for a name, or had a regular name that linked to an obviously commercial blog. Some people don’t want to do this because they want “more comments”, but allowing that crap does not help you build a community. No one wants to engage in a discussion with a spammer, so don’t get sucked into allowing them to live.

Every blogger should also have a Terms of Use page that outlines what you do and do not find acceptable. Then you can enforce at will.