That got me thinking ... I'm sure it wouldn't be too hard to program a clever spam bot that would utilize the DOM to read rendered HTML (kind of like how JAWS does), instead of looking for email patterns. What about using a trick like this:
And if it's absolutely important that the email address appears visible to user (like, firstname.lastname@example.org), just cut that as a GIF instead of using plain text. I haven't tried it yet, but I'm thinking, that could be the way to go.