WM5 built-in application for VoIP (SIP) in Smartphones?

[Guest FoxTango]

Hello all

Is there a built-in application in WM5.0 for SIP-based VoIP?

It would be nice being able to use a WiFi-enabled Smartphone like the QTEK 8310 as a SIP-client.

I have stumbled over a few commercial VoIP applications (like XTEN) but only for PDAs. I remember seing an example WM5 application by Microsoft at the time of WM5 launch. What became of that?

Kind Regards

FT