One interesting use that is (as far as I know) unique to Perl, is using the trinary as an Lvalue. That is on the left hand-side of an assignment as in this (rather silly) example.
#! perl -sw
use strict;
my (@aboveC, @cOrLess);
while (<DATA>) {
# $1 := name, $2 := grade
m/^(\w+)\s+([a-f][+-]?)$/i;
# if the grade is one of these
0<= index('A+ A A- B+ B B- C+', uc($2), 0 )
# add name here if not add name here
? $aboveC[@aboveC] : $cOrLess[@cOrLess] = $1;
}
print "Above C students: @aboveC\n";
print "C or Less students: @cOrLess\n";
__DATA__
homer f
bart d-
marge c+
lisa a
which gives
C:\test>195952
Above C students: marge lisa
C or Less students: homer bart
C:\test>
Well It's better than the Abottoire, but Yorkshire!