Today I got the hint from a colleague that there’s some app from RockstarApps which enables to optimize CSS and JS in Eclipse on the fly. I just did some work on my imagemap_wizard TYPO3 extension and it seems to work pretty well - therefore I highly recommed to checkout the Rockstar WebOptimizer if you’re developing Javascript applications.
It seems that it also supports CSS sprite generation - this might be a followup tomorrow ;)