dd should accept M,G,T,... for sizes
dd accepts 'k' suffix to mean multiply-by-1024. GNU dd accepts other suffixes to represent mega, giga, etc.
Updated by Josef Sipek about 10 years ago
I checked the GNU dd's man page. They say:
BLOCKS and BYTES may be followed by the following multiplicative suffixes: c =1, w =2, b =512, kB =1000, K =1024, MB =1000*1000, M =1024*1024, xM =M GB =1000*1000*1000, G =1024*1024*1024, and so on for T, P, E, Z, Y.
I added [MGTPEZ] but not [MGTPEZ]B which would require a whole lot more parsing code.