Address Size
H Ratio = log10(# of objects)/available bits
2n objects with n bits: H-Ratio = log102 = 0.30103
French telephone moved from 8 to 9 digits at 107 households ? H = 0.26 (~3.3 bits/digit)
US telephone expanded area codes with 108 subscribers ? H = 0.24
Physics/space science net stopped at 15000 nodes using 16-bit addresses ? H = 0.26
3 Million Internet hosts currently using 32-bit addresses ? H = 0.20 ? A few more years to go