I have been wanting to prevent web crawlers that collect email addresses for spam lists from collecting addresses from my site for a long time but never really liked the idea of directly encoding the email address such as tom.jones[AT]jones.com because I felt too many website visitors would not figure out what was going on and know to edit the [AT] to a @ .
So I decided to do what I should have done a few years back - do a search to see what alternatives there might be. Well I found a brilliant one AddressMunger.Com. Absolutely brilliant! Stops the crawlers and is totally transparent to the user. If you have a blog or a website - you will LOVE this :-)
And of course Wikipedia has something to say on Address munging in general.