I believe this will be one really good feature of GMail, the ability to send and receive phone calls through your computer while you are logged into your email account (available to USA only). Since I use Google Voice this is automatically added to my GMail account for use. However at first try this morning I have not been able to get it to successfully call my mobile phone. While the phone rings and I can answer it I cannot hear anything on either the phone nor my headset on the computer. I continuously keep getting error messages like this:

Sorry! The voice chat with (xxx) xxx-xxxx failed due to an error [Code: 3 Remote: true] at 9:18 AM.
Click here to report this to Google.

I have been reporting the issues to Google but I wish this would just work. The best part that got me interested is that first it was automatically linked to my Google Voice account, second it is easy and free to make calls to any land line or mobile phone in the USA. International calls are available too at rates as low as $0.02 per minute. Have you been able to get Google Voice to work from within the GMail interface? What are your thoughts on this service? I think it would be beneficial if you remain logged into your GMail account all day however I already have my Google Voice number ring my mobile phone.