As far as I can tell, Mac OS did not adopt the GNU fileutils, but they did adopt this nice feature. I find it handy when I'm using a Terminal to use ls -lh, so I don't have to count digits to figure out the sizes. Here's an example:
% ls -lh
total 5504344
-rw-rw-r-- 1 paco staff 42B 3 Aug 20:59 01.gif
-rw-rw-r-- 1 paco staff 872M 3 Aug 22:43 BTV Movie 001.mov
-rw-rw-r-- 1 paco staff 1G 3 Aug 22:47 BTV Movie 002.mov
-rw-rw-r-- 1 paco staff 2M 30 Jul 14:54 GameServices.pdf
-rw-rw-r-- 1 paco staff 1M 3 Aug 17:29 befw11s4_v4_ug.pdf
-rw-r--r-- 1 paco staff 460B 3 Aug 16:58 chiras1-nt
[robg adds: If you use the -h option a lot, you might want to create an alias for it -- I use lsh, which is an alias for ls -alh, the options I use most often with ls.]

