Copyright is something we should be trying to defeat or work around.

Web developer/designer over here; my total editor, languages, 8 or so project folders, Windows XP virtual install (complete with Baldur's Gate 2, Dungeon Keeper and a few other choice classics) and audio/video files all total something like 24gb. I don't try to keep it down, that's just what it comes to naturally. I bought myself a stack of 2.5" 64gb SSDs at about $160 each, and put them in my laptop, netbook and desktop (the wife's iMac is the only machine in the house that still uses platter drives, and it's because she uses something like 200gb of storage there). Granted, most of the audience here is probably Windows users, but if you're already on some flavor of Linux for a machine or two, it is very VERY easy to get away with a 32gb SSD (which is down at the ~$100 range). And like Jeff says, it is easily the best performance-related purchase you can make.