As I logged into my Gmail account a few minutes ago I was presented with a delightful popup message informing me I can now make phone calls from within my Gmail account. Google Voice has been available in the US for some time and further international rollout has been promised and now delivered to Aussie Gmail users.
Phone calls can be placed to landline or mobile numbers for very competitive rates: US$0.02 per minute to landlines and US$0.14 per minute to mobiles. That's around half the cost of calls made with Skype and paired with Google's free Video chat and new Google Hangouts Skype must surely now be history. I can't think of a single reason to use Skype for paid services.
Calls to mobiles from your home phone cost AUD$0.30 per minute (may be plan dependant) so calls to mobiles are actually cheaper with Google Voice than with our national carrier, Telstra. What's more, depending on your home phone plan, calls under 10 minutes to landline numbers are also cheaper than Telstra.
US customers still get the best of Google Voice such as free local calls (for now) and text messages.
For more details and to see if Google Voice is now available in your country check out the official Google Voice blog.