More Capturing

while(<>) {
  if(/http:\/\/([^\/ ]+)/) {
    print $1, "\n";
  }
}
http://slashdot.org/~BillG/journal
http://www.stuff.co.nz/sport/beachvolleyball
http://on.tv/tonight
slashdot.org
www.stuff.co.nz
on.tv