DruCall (the WebRTC module for Drupal) is being updated to use
JSCommunicator from http://jscommunicator.org
I've deployed the new DruCall as an alternative to the existing service
for free calls to Lumicall:
http://www.lumicall.org/drucall
(new, based on DruCall/JSCommunicator)
http://webrtc.lumicall.org
(existing service, based on tryit.jssip.net)
If it works in your browser, you should be able to dial any phone that
has Lumicall installed - just dial the number in E.164 format, e.g.
+447771231234 for a UK number.
I'd be interested in any feedback about this. It would also be really
useful to find somebody who is good with CSS who can help make
JSCommunicator look a little bit more pretty.