"The real annoyance is that Windows and Mac OS X both insist on measuring in GiB, but use the "GB" suffix like they're just trying to confuse you. Hence the icon."
Yeah, both major operating systems are trying to confuse you, not the HDD manufacturers. *sigh*.
Windows and Mac OS X have been *correctly* reporting in "MB" and "GB" since before MiB and GiB were even invented.
MB = megabyte (2^20 bytes)
GB = gigabyte (2^30 bytes)
MiB = Men in Black, a movie starring the Fresh Prince
GiB = Girls in Black, a little known blaxploitation sequel