The version from textmate itself was just i little bit too basic.

Here's my simplified version...

<a href="${1:`

   # if the clipboard contains a single line, let’s use that

   export __CF_USER_TEXT_ENCODING=$UID:0x8000100:0x8000100

   if [[ $(pbpaste|wc -l) -eq 0 ]]

      then pbpaste|perl -pe 's/&(?!([a-zA-Z0-9]+|#[0-9]+|#x[0-9a-fA-F]+);)/&amp;/g'

      else echo http://site.com/

   fi

`}" ${2:target="${3:_blank}"} ${4:title="${5:${TM_SELECTED_TEXT:Link text...}}"}>${6:${TM_SELECTED_TEXT:Link text...}}</a>$0

For sure their can be made some changes .. so i'll listen carefully :-)