Re: What? No lawsuit about RAM?
Its because apple uses base 10 to calculate disk space (as does pretty much every other hard drive vendor). Interestingly most operating systems still used a base 2 to display - which leads to confusing results as the user sees much lower storage than was previously advertised.
Really interesting is that for a while apple OSX display in base 10 too, which means a 250GB hard drive reports as 250GB even though it is actually a little less (something like 240GB or so I think).
The formatted capacity may also be taking into account EFI Partition, Restore Partition, Wear-leveling blocks, Write-buffer area and a whole bunch of other stuff I have no idea the meaning of.