[mikeo1313]

As this is an interest of my own I gathered these links while I coincidentially ran across this thread.

http://www.touchxperience.com/

http://handheld.softpedia.com/get/Sy...ig-66714.shtml

http://www.voipphreak.ca/2008/03/29/...sing-asterisk/

http://forum.xda-developers.com/show...highlight=voip

http://forum.xda-developers.com/show...highlight=voip

http://forum.xda-developers.com/show...highlight=voip

http://forum.xda-developers.com/showthread.php?t=426583



Something you might want:
http://ovpnppc.ziggurat29.com/ovpnppc-files.htm



Me personally I haven't tested any yet. When I get the chance I'm going to first try the voip config software links. If none of those work I'll be giving the htc raphael voip app a shot from the last xda link. As far as the openvpn link, if you have an asterisk you probably would want to give openvpn a go.