chromatic has a good little chunk of code there, or you can also do this:

use URI;
sub blahify {
  my $relative = shift;
  my $base = shift;
  URI->new_abs($relative, $base)->as_string;
}
[download]

I don't see why you're passing a reference in... but you can season this one to taste.

-- Randal L. Schwartz, Perl hacker