Previewed at WWDC, launching in the fall.
Increase OS X Performance: Swap Partition
The solution: create a dedicated swap partition (which is the method Linux uses by default) for OS X to page to. In searching the web to find out how to make this alteration, I found a number of sites with prodcedures to follow. The one I felt most comfortable using as a guide was setup by Andy Moraitis. In looking at his procedure and through back-and-forth e-mail with Andy, it's clear that he has a deep understanding of the mechanisms of OS X and its paging system (and that of its predecessor, NEXTSTEP). And lucky for those with a mind to increase OS X's performance, Andy has recently put out an even more detailed version of his procedure, which you can get from his iDisk. (Note this guide is in Tex-Edit Plus format--download this editor from VersionTracker.)
Truly, if you're even remotely comfortable with using the the OS X Terminal shell, this modification is time well spent.