That's cool! Admittedly, you might be restricted as to perl versions, since it relies on vstring functionality. It occurred to me that there might be a golf like solution involving some kind of GRT. It's probably quite fast as well.

I'll even name it for you: the Gutta Percha Transform :).

Hm, golfing with GRT? No idea how, but anyway, here's a possible starting point:

$ perl -le '$,=$/; print @ARGV[ map { unpack N, substr $_, -4 } \
    sort map { eval("v$ARGV[$_]") . pack N, $_ } 0 .. $#ARGV ]' \
    1.2.1.1 1.1.1.1 1.11.1.1 1.1.1.66 1.1.1.9
1.1.1.1
1.1.1.9
1.1.1.66
1.2.1.1
1.11.1.1
[download]

OTOH, that previous version could easily be golfed (ok, just a little) by dropping the initial map (which is useful only when using this snippet "for real" - you know, using sprintf and returning a list):

$ perl -e 'printf "%vd\n", $_ for sort map { eval "v$_" } @ARGV' \
    1.2.1.1 1.1.1.1 1.11.1.1 1.1.1.66 1.1.1.9
1.1.1.1
1.1.1.9
1.1.1.66
1.2.1.1
1.11.1.1
[download]

--
AltBlue.