You should be using something unique to your site in addition to the widely-used countermeasures. Until your site is worth targeting explicitly, that little bit of custom code can make it uneconomical to spam your site.
You can also join with others who work to stop this kind of spam. For example, Project Honeypot ( http://www.projecthoneypot.org/ ) offers honeypots to trap all kinds of spammers, including comment spammers.
If you're expecting some kind of 100% solution to spam, I doubt that will never happen. The best anyone can do is combine a bunch of decent solutions, preferably in unique combinations, and hope to reduce spam to a manageable level. If one countermeasure blocks 50% of spam and another 70% and another 90% and their failures are independent, you're down to 0.5 x 0.3 x 0.1 = 1.5% of spam getting through. Chain enough partial solutions together and you get something better than any one alone.
The assumption was that the solutions were chained and that they would never see the things that failed before that. But I guess I only stipulated that the failures were independent, when the math I wrote meant that the successes should be independent, as well.
You can also join with others who work to stop this kind of spam. For example, Project Honeypot ( http://www.projecthoneypot.org/ ) offers honeypots to trap all kinds of spammers, including comment spammers.
If you're expecting some kind of 100% solution to spam, I doubt that will never happen. The best anyone can do is combine a bunch of decent solutions, preferably in unique combinations, and hope to reduce spam to a manageable level. If one countermeasure blocks 50% of spam and another 70% and another 90% and their failures are independent, you're down to 0.5 x 0.3 x 0.1 = 1.5% of spam getting through. Chain enough partial solutions together and you get something better than any one alone.