This will be a sort of Ajax solution - no worry - but the first thing I want to show you is simply how effective CSS can be.
In short we are gonna create a GUI looking like the one found on Live.com - example
See the hovering effect? That's cool and since I needed to create such an effect for a project I am (still) working on - I decided to try to mimic it.
The basics
I started by simple feeding the images into a repeater:
This will feed all png files inside the "theimages" directory

to the repeater. The repeater HTML code looking like this:
The databound event then just sets the imageurl of each image:
Which renders all the images like this:
