This one won't be obvious until you find the hidden clue and follow its instructions.

Running the program reveals the clue.

sub sub {$"='
jJPPJPJJjppHjpHAjpHAjpHAjpHAjPhAjpHAjpHAjpHAjpHAjpHAjpHAjpHAjpHAjpHAjp
HAjphajphajPhAjPhajPhaJPhAjphaJPHAJPHAJPHAJPhAJPhaJPHaJphajPhaJphaJPhA
jpHAJPHAJPHaJphajpHAjPhAjpHaJpHaJphaJphajPhAJPHAJPHAjPhAJPHaJpHAJPHAJP
HAjphajpPhjJPpjPJJAHHJaAAjAPhhJPJjahaPaPpaapaaAHahjpjJahaJAPPJapaaJPJJ
aPpjaPpAaPAJapAjAPaAAPhpjpjJapHaapaaAhJhAhJHaPjAaPAHAPaAJPHJJpjjahjhap
jaahapApAaJPjjaJPPApjaaHjjAPPjjPJjahAHaPpAahajApPJjpjJapJajPJJJpJPjphP
AHjjApHjjpjpjpjjAHHjjjppjpjjAHHjApAAAHpjAHAjApAAApHpAHjHAppAApHHApHpjp
JJApjaapHpApAjjpjjApAAApAjAppAahAjjpjjAppAApHpjpjjApAHAHApAppAApHAjpHj
JPjjAhapaPPaaPHaJpjjAPhHAHjpjpJJApAAAPhaApJaApjhaHJhJPhPjPJjjPJjAaJJap
aaAHjPapApaPHHAhJPAphaJpJJahhjJJppjpJJAhhjaPjAjPJjAHJhApAaaPjaaHJPApjH
APPjJPjjjpPJAHjPaPaaaPaHApAAAHPJjpjjahjhapAaapJaAHjpaPjHAPPJJPJjaPpaaP
HpJPJjApAAaPHAAPJAaPjhaHjHjppAJPjjApaPAPhHAHJPJpjjAHaJAppJapaaJpJJApJh
AppJApjAahJPJPHPJpJJAhJHApAAAHaJJPJjAhhJjjppjPjjAHhJaaPhAJPpAPJAAaJJap
pjAAHAjpHpjpjjjpjjAjpAApHpjpjjAHApAppAApHAjpHjjpjjAHAjAHjpAHpAjpjjApHH
ahaaahAjjpjjApAjAppAApApApApaPAAahjpApAAApHpAHAjjpjjApjHApHHApHjApHHah
JPjpjJaHJhaPJHaPPJapAaapHAApaaAHJhjphPJPjjjpJJahHJJjpPJpJJJPphJPhajpha
JPHAjPhAJPHAjphajphajPhAjpHAJPhaJPHAjpHaJpHaJpHAjPhAJPHAJPHAjPhAjPhAJP
haJPhajphaJPhAJPhaJPHaJpHAjphajphajphaJPhAjPhAjpHaJPhAjphaJPHaJPhaJpha
JPHAjpHAJPHAjphajPhAjPhAjpHAJPHAJPHaJpHaJpHaJpHAjPhAJPHAJPpHjJPpahHpAH
hPppApAjJJJaJjJhAAJapaJJaaHAaaApaappPhPPPPjjaahJAJhAHJJpPPPJAPapHPJAPh
';$_=$"&&s+\n++g;{$"!~s((.))() or$O=$O<<2|index lc"jApH",lc$1;unless (
++$%%4){'~'ne($O=chr$O)?print$O:exit}redo}}$==& sub(liverpole.8/13/06)
[download]

Update:  modified clue to take advantage of Ray Smith's observations.

Update 2023-07-12:  modified to get rid of no longer supported $* variable