Using the sip with VoipDiscount.com (part of Betamax, or however it is call the company) and it works much better than it does with the N900. I'm very happy about it especially for the sound quality and the ability to initiate the connection to the voip account by simply selecting from the contacts to call someone using sip. The phone becomes a little hot after 20 minutes but temperature remained constant for the next hour of the call. I think for the future long calls I will use a handsfree. You have the option to setup more than one accounts but I haven't tried that, HIH