What is the best way to minify drupal's aggregated javascript (automatically)?
I created a new module to tackle a lot of the aggregation issue &amp; I hope to get a large chunk of it into D8; and yes it's a D6 module: http://drupal.org/project/advagg. Uses the jsmin+ lib for compression of JS and the CSSTidy lib for CSS compression. Main advantage of this is the css/js aggregate file doesn't change names unless it needs to; these files also have a 1 year cache lifetime &amp; has imagecache generation so 404s to your CSS file should be a thing of the past.

Update: AdvAgg 7.x is being developed and comes with minification of JS as an optional sub module. Other D7 options:
http://drupal.org/project/speedy
http://drupal.org/project/uglifyjs