will match free floating valid protocol + urls in text ... will not touch the ones wrapped in a tag, so that you can auto-link the ones that aren't :) couple of things to know :
1. if the url is next to a tag this won't work (eg : <br>http://www.acme.com), the url must either start with a \s, \n or any character other than >.
2. the pattern will match the preceding \s and \n too, so when you replace put them back in place $1 will either be \s or \n, $2 will be the exact match
vb usage :
set re = New RegExp
strResult = re.Replace(strText, "$1<a href='$2' target='_new'>$2</a>")