This line:

  use warnings;
  use strict;
  use File::Find;

  my %hash;
  my @temp;
 
  my $dir = shift @ARGV;
  die "Give me a directory to search\n" unless (-d "$dir");
  File::Find::find (\&wanted,"$dir");
 
  print "-"x20,"\n";
  foreach my $key (sort keys %hash) {
    print $key, "\t:\t",$hash{$key},"\n";
  }
 
sub wanted {
#   don't attempt to read a directory.
  return if (-d $_);
  my $fname = $File::Find::name;
  @temp = split(/[\/\\]/, $fname);
  $fname = $temp[-1];
# Make sure there is an extension. We check for a
# trailing period even though on Win32 it shouldn't happen
  if (($fname =~ /\./) && !($fname =~ /\.$/)) {
    $fname = lc($fname);
    @temp= split(/\./, $fname);
    $hash{$temp[-1]}++;
  }
  else {
    $hash{"no ext"}++;
  }
}
[download]

Update:
I Changed a few more things around. I went right for the filename since a "." in a directory could mess things up as well.
$array[-1] so that we don't have troubles with files like "blah.txt.sh".
And we now account for no extension at all.
This code could make use of File::Basename as well.