Only slightly off topic but answering a question further back in this thread. I just tried a SIP (ippi) call (video). This is the first time that both ends of the call were using the Jitsi client. The client reported that the connection was encrypted. This was automatic and required no action on my part to set up...
The call was from the UK to Cambodia. Sound & Video were excellent...
Shame there's no Jitsi client for the N900. It's open source will someone with the skills do a build for the N900? Please. I don't have the time/skills... Willing to pay...

http://t10282.voip-jitsi-user.voipfo...00-t10282.html