Unfortunately, when copying and pasting the right-to-left version, the text becomes left-to-right again (i.e. backward).

That is super interesting! Thanks for sharing.

Sadly, however, none of these techniques alone will work on a widely spider-able site. If you have a sufficiently large pool of visible email addresses, it suddenly becomes worth while to crack your single method and spider you specifically. I'd prefer to show email addresses in plain text, but if a client begins requesting them too quickly, replace them with a link which pops up a javascript blockade with a captcha.

That said, one of these methods is probably worth using for a single email address on a personal site. However, my email address has been widely distributed in plain text for several years and Gmail has more or less solved the spam problem for me.

Yes, data are helpful. Regularly updated data: more so - because they would enable us to see whether/when spammers are adjusting their methods to accommodate our latest obfuscations.

I wonder why so many people are claiming "something AT somewhere DOT com" does not work when your reference shows that it works nearly perfectly.

Whoa that's pretty cool. I use a mix of javascript and html entities on my company's site. Seems to work pretty well.