I wrote this about 5 years ago, when I was first learning Perl. It was the product of a moment's insight followed by several hours of tweaking.

push(@dat,'push(@dat, abs())if(not(hex($_))or ($,cmp reverse()));'
.'eval$l;$,= chr(74);$_=pack(v,$_); reverse();push(@dat,"hda|v? r'
.'ev|xo|cm|rp|se|elsif|eval");$_=@dat[0];s/.{136}$//;s/b/el/;s/ch'
.'/h/;s/^.|_|\d|[^\w ]//g;s/$dat[2]//ig;print$,.$_;');eval@dat[0];
[download]

I know it is not the most advanced JAPH out there, but I have always been fond of it. I'm posting it here as my first entry, in commemoration of a joyful time in my life. I hope others find this code interesting and fun to unravel. Any thoughts?