don't quote me on this, but these may work:
Yahoo
Code:
<a href="http://edit.yahoo.com/config/send_webmesg?.target=$YAHOONAME&.src=pg" target="_blank">
<img src="http://opi.yahoo.com/online?u=$YAHOONAME&m=g&t=1" alt="Send a message to $YAHOONAME" border="0">
</a>
ICQ
Code:
<a href="http://wwp.icq.com/$ICQNUMBER#pager" target="_blank">
<img src="http://wwp.icq.com/scripts/online.dll?icq=$ICQNUMBER&img=5" alt="ICQ status" border="0">
</a>
<a href="http://wwp.icq.com/scripts/search.dll?to=$ICQNUMBER">
<img src="/path/to/some/add/user/graphic.gif" border="0"></a>