Two things are different now: first, it's OS X times, and second, RAM is cheap and everyone has (at least) 512MB of RAM, it seems. Well, in OS X, you really wouldn't need nor want a RAM disk. Besides, there are almost no utils to create RAM disk anymore in Panther. Who needs a RAM disk? Well, all of us who have plenty of RAM but an antique Mac, do. Like me: i have 640MB of RAM in my old iMac G3 500, running 10.3.3. It would be a great idea to dedicate some of this amount of RAM to better things than system memory.
So I created a RAM disk (with the excellent freeware Disk Velox) and then moved the Safari cache (from ~/users -> Library -> Safari) onto it. Then I created an alias of the new RAM-based cache folder and placed it back in the default Safari folder. So now the Safari cache points directly to the RAM disk. And I started to surf the Internet, and I couldn't believe it! Never had my usual sites had opened so fast! VersionTracker, MacFixIt, MacOSXHints, everything is instantaneous. Really makes a huge difference in browsing experience. So, who needs a DP G5 2,5 when you have a RAM disk :-)?
Some problems remain, though: there is no OS X RAM disk creator with an option to save the RAM to a disk image on shutdown, so everything is lost the next time you restart. It would be great to be able to save the cache between startups. Second problem: it would make sense to open the RAM disk before launching Safari, so the previously-saved cache is ready to be used. I think some little AppleScript would do that, but I have no AS skills. Right now, I enjoy my speedy Safari, but I hope someone can suggest some further enhancements.
[robg adds: I tested this, but didn't see any change on my reasonably fast machine. I'll try to test it later today on our G3/500, where I expect there will be a more notable increase in speed. Disk Velox is a really simple-to-use RAM disk creator, though -- just enter a name and size, click a button, and you're done. Quite nice...]

