With this simple plug in for Expression Engine you can easily hide anything you want from robots.
The plug in dynamically hides html from users and asks them to enter the correct "turning number" before they can view the html. This plug in uses no JavaScript or CSS just a form post to determine if the person entered the correct number.

Live example here http://chanticleer-yacht.com/index.php/contact/


How to install the plug in:
FTP in to your site browse to the "system" folder ( or whatever you renamed your system folder to )
Open the "plugins" folder
Upload the "pi.mailguard.php" to that folder

How to use the plug in:
"
Put this tag in your Expression Engine template:
{exp:mailguard:hide
file_path='D:/live_websites/foobar/images/captchas/'
html_path='website.com/images/captchas/'
instructions='Enter the Number In the Box' }
Stuff you want hidden
{ /exp:mailguard:hide}
"
file_path is the full path to the place you want it to save the images.
html_path is the web path to the same location as the file path
instructions is what is shown only before a turning number has been entered

Link to the discission about the plug in on the expression engien forums http://expressionengine.com/forums/viewthread/122786/