I stopped by the Apple store in Tyson's Corner yesterday, and saw the 250GB LaCie d2 multi-interface external HD now costs a hair over $1/GB. In that same product line, there's a 400GB drive at $449, and a 500GB model at $549. On the Apple Store website, the Porche-designed 250GB LaCie p3 external FireWire drive is only $249.
Wow.
I remember my first internal hard drive for my Mac SE, back in 1988. It cost around $400, and it had a capacity of 45MB. About 18 months ago, I told myself I wouldn't buy another disk until I could get at least .25 TB at less than $1/GB. If nothing else, it makes rotating backups of my 20GB laptop disks much easier to bear.