I use this regex in onACTION/NOTICE/TEXT events to catch links (and server spam):

Code:
on *:TEXT:*:#:{
  var %text = $1-

  ;*** Ignore non-links ***
  var %islink = $false
  if ($regex(%text,/(www\.|http\:|\.com|\.net|\.org|irc\.|\/server)/i)) %islink = $true
  if ($regex($3-,/[aeo]wwww*\./ig)) %islink = $false
  if (!%islink) return

  echo -a $nick posted a link in $chan
}


It's fairly accurate in finding links, and it doesn't match if someone says "awww..." or "owww..." etc.

-genius_at_work