A "low-tech" alternative would be:

    my $filename = "utf16le.txt";
    open IN, "< utf16le.txt"
        or  die "Can't read $filename: $!\n";
    local( $\ )= \2048;
    my $utf8str= "";
    while( <IN> ) {
        $utf8str .= pack "U*", unpack "v*", $_;
    }
[download]

which should even work in Perl 5.6, though I wouldn't do much with UTF-encoded text in Perl 5.6 (I don't even completely trust 5.8 for that yet).

                - tye