I have implemented a reCAPTCHA process to display my e-mail adress on my page, called MailHide. This is the URL:
http://mailhide.recaptcha.net/ If you don't remember, a CAPTCHA is a word you are asked to enter from a picture you see, and the idea is to protect against spam. Basically, it allows me to give you my e-mail adress and you need to answer a CAPTCHA process to see it, spam trawlers cannot get at it.
Here is my e-mail adress: ljuv
...@gmail.com
So why this?
The beauty of reCAPTCHA over other similar solutions is that when you fill it out a reCAPTCHA you are also doing a good thing, by helping the Internet Archive (www.archive.org) digitise books. In a reCAPTCHA you see two words. One is a word the project needs help deciphering, and another is a known word. The process then assumes that if you fill out the known word correctly, you knew what the indecipherable word was. This goes back into the project and aids the digitizing of books.
reCAPTCHA is free for webadmins to use:
http://recaptcha.net/