If I’m doing larger content managed sites I tend to combine and compress scripts server-side, but for smaller sites I used to not bother. Manually combining and compressing files isn’t much fun, and you’ve normally got better things to do with your time. Yes you could install a server-side library like minify, but sometimes that’s not the best option.This is where CodeKit comes in handy.
For me it takes all of the hassle out of optimising scripts. It makes working with stylesheet metalanguages a breeze. I’ve been using LESS for a while and recently switched to SASS, and the way it just automatically compiles and minifies is great. I would definitely recommend it to anyone.