The top rated answer has a couple of interesting techniques to get around this problem.
Also, not everyone has a Gmail account. I'm sure virtually everyone on HN does, but some of us also wind up making websites for people who are less savvy. So techniques for obfuscation could still be useful.
True, but I thought spam detection was something that was 99% effective with bayesian filters. Sure, not all of your clients will have them, but I figure that people who are truly worried about this sort of thing will either be running their own mail servers, or will pay someone to do it for them.
I frankly cannot understand why, but on my old yahoo account at least 50% of the spam gets through, including those in suspicious russian (which, since I do not speak the language and have always flagged as spam, makes zero sense to me).
So, either the gmail engineers are better than most, or it is still not trivial to get it right.
Also, not everyone has a Gmail account. I'm sure virtually everyone on HN does, but some of us also wind up making websites for people who are less savvy. So techniques for obfuscation could still be useful.