#!/usr/bin/perl -w
use strict;
use List::Util qw(shuffle);

print map { join '', $_->[0], shuffle(@{$_}[1 .. $#$_-1]), $_->[$#$_],
+ ' ' }
      map { [ split // ] }
      @ARGV ;
[download]

although that doesn't really work for 1-letter words

update

#!/usr/bin/perl -w
use strict;
use List::Util qw(shuffle);

print map { !$#$_ ? $_->[0].' ' : join '', $_->[0], shuffle(@{$_}[1 ..
+ $#$_-1]), $_->[$#$_], ' ' }
      map { [ split // ] }
      @ARGV ;
[download]