how did this get modded up? this is misinformation.

du(1) man page (snow leopard):
          -H Symbolic links on the command line are followed, symbolic links
                          in file hierarchies are not followed.

          -h "Human-readable" output. Use unit suffixes: Byte, Kilobyte,
                          Megabyte, Gigabyte, Terabyte and Petabyte.

df(1) man page (snow leopard):
          -H "Human-readable" output. Use unit suffixes: Byte, Kilobyte,
                          Megabyte, Gigabyte, Terabyte and Petabyte in order to reduce the
                          number of digits to three or less using base 10 for sizes.

          -h "Human-readable" output. Use unit suffixes: Byte, Kilobyte,
                          Megabyte, Gigabyte, Terabyte and Petabyte in order to reduce the
                          number of digits to three or less using base 2 for sizes.

this is exactly same output as man pages fro those two in FreeBSD 6.1

this is man page from debian linux:
              -h, --human-readable
                            print sizes in human readable format (e.g., 1K 234M 2G)

              -H, --si
                            likewise, but use powers of 1000 not 1024

so it seems to me that behavior of darwin is exactly same as gnu tools.

very gently