A very interesting discussion at Slashdot earlier this month about how to stop spam.
There were many suggestions involving images with obscured characters, but that's just not acceptable for business.
A lot of these suggestions are fine for personal sites; but if you're actually in business they aren't practical.We use Javascript. You don't want to make life more difficult for the person trying to correspond - the point is to raise the cost to the spammer. If they have to add a Javascript parser to their spider, it's going to slow them way down. It's not going to make financial sense for them to do a custom solution for each site (and if they do, the "image" methods will break down as well).
What do we do for our own clients to lighten the spam load?
Keep reading Foiling Email Harvesters and Coping with Spam