Thanks for the kind words nextgen
In case you missed it on raven's site there is an alternate sprite pack available for the block http://www.ravenphpscripts.com/postt20295.html
It should give you a little background on how it is put together, as well as tips for customizing.
There are also the numbered list sprites, which are a questionable usage of sprites, and were only used to keep ie7 compatibilty. But here's some custom versions of those:
There are times sprites make sense, and other times they do not. For instance, I tried creating a sprite version of country flags, but the resulting background image was 60kb, plus a ton of css, which didn't make much sense to display a few flags on a given page. Although if every page of your site had 25 different flags on it, then it might start to make more sense...
Sprites are great for icons and image-mouseover effects, but not so great if the resulting sprite image and css becomes too large. Another recent approach to icons is using a custom icon font, which offers greater versatility regarding icon size, but may not be well supported on all platforms, such as mobile devices.
Guardian recently recommended html kickstart
(very cool) which shows a good example of using a font for Icons/Glyphs.
or customize one at icomoon
and if you don't know how to use custom fonts, check out font squirrel (also very cool) which has ready to use font packs or a font face generator
Just another approach that some may like