NOW we're talkin' fast! On my AMD64 X2 workstation with my original 11818 addresses, ip4sort beats the pants off of everything, 258% faster than gloryhackish, and a whopping 727% over Schwartzian Transform. At 100,000 addresses, the numbers are 281% and 1169%, respectively, and at a million it's 248% and 1140% (looks like the curves are flattening a bit way up there). Good work!

So guess who's just decided to use ip4sort from now on? :-) Thanks!