Maybe it's my fault, maybe not. The truth is that I had some problems optimizing my webserver load with CSS Sprites, a nice, clean technique to max the efficiency of every image. Let's go into details:
I used a set of flag icons (taken from Fam fam fam) in a site admin zone. There are 247 flags, sweet and small (16x11) and that's all I needed. In this admin you can browse through tables with tons of data, to the point that all of the flags may be shown at once. More than once, in fact. So in a clean-cached browser you probably end requesting 247 images from the server. Even if the only answer were a 304 Not modified (in another scenario) they're too many requests. No way, being the "optimizer" I am, I need to change that.