[dandersch]

Very interesting. It seems for his own email the author has opted for a combination of the CSS display none technique and a XOR cipher:

  <span class="hidden email"><b>999a8f84898f98</b>aa<b>878b8386c4</b>999a8f84898f988785989e8f84998f84c4898587</span>

[lenwood]

I noticed that, too. Technically I think this is a version of JS conversion. Interesting that he doesn't specifically mention XOR in the article. He does suggest combining methods though. I suspect this is effective.