I hope someone has as much fun unraveling this as I had creating it.

@s{keys%::}=();bless{};;*{(sort grep{!exists$s{$_}}keys%::)
[1]}=sub{$n=0.5;{print"\r",map{rand(100)<=$p?$_:' '}split//
,"Just another Perl hacker,";$p<0&&$n<1&&last;$n*=$p>110?-1
:1;$p+=$n;select$q,$q,$q,.04;redo}print$/};${bless\$|}-=1
[download]

One hint is to figure out the order in which things really happen, and why.