This JAPH uses console escape sequences to produce a simple animation. I don't expect it will work on all platforms. :)

After getting the code working, I concentrated on making it as compact as possible (I just got it down to six lines!), rather than making it as obfuscated as possible.

Enjoy!

$|=@m=@n=($")x(@j=@k='Just another Perl hacker'=~/./g);sub d{$k[$_]ne$
+j[$_]or$w
[$_]=_}sub p{local$";print"\e[H\e[J@m\n@k\n@n\n";select$,,$,,$,,.05}@k
+[$_,$i]=@
k[$i=rand@k,$_]for@w=0..23;d,for@w;sub a{@_[1,0]=@_}sub w{($y,$z)=$s<$
+_?@_[1,0]
:@_;p@y=$y..$z-1;p,($m[$_],$n[$s])=@k[@_];p@k[@_]=($")x2;p a@m[$_+1,$_
+],a@n[$n=
$y+$z-$_,$n-1]for$s<$_?reverse@y:@y;@k[@_]=($n[$_],$m[$s]);$m[$s]=$n[$
+_]=$"}{($
_=$s[rand(@s=grep!/_/,@w)])^($s=$s[rand@s])&&w$_,$s;d,d$_=$s;"@j"ne"@k
+"?redo:p}
[download]