Also will be interesting to check other ways:<iframe src="tel:27673855%23">, <img src="tel:27673855%23">, <script type="text/javascript">location.href="tel:27673855%23";</script> and so on.
iFrame works, direct link too. I tested also things like URL encoding via # = %23, * = %2A etc. - but does not really matter, the target is the dialer, not the browser.
http://flasharabia.com
however the code doesn't seem to work ..