CSS Sprites online tools
CSS Sprites it was a very popular technique for a long time. Biggest benefit from it: reduce number of the requestes to the server, and speedup whole website / loading image assets. Working with CSS slides is really painful Usually you are starting from PSD then you have to decouple them to separate images, then merge them again to one image, and then mark position of each element in the CSS file.
Couple useful tools to work with: