Adding a rel='hover_effect' effect to any HTML tags will turn the tag to a 0.5 opacity and on mouse over it will fade it quickly to full opacity, on mouse out it will fade back to 0.5.
If javascript is disabled, the html tags with rel='hover_effect' will simply do nothing. So it wont cause any problems for people with JS disabled.
Requires the prototype and scriptaculous frameworks.
Example of use:
<img src='image.png' rel='hover_effect' />
Note: Does not work brilliantly in IE due to IE's rubbish effects engine... opera, firefox etc do it very smoothly :-)
Install: Just add the code to the <head> part of the page inside <script> tags.
