Google has started offering Gmail calling outside the US in 38 new languages. You can now buy calling credit in your choice of four currencies (Euros, British pounds, Canadian dollars, or US dollars). Furthermore, there are no connection fees: you only pay for the time you talk. Google is also lowering its calling rates to over 150 destinations around the world; see the International calling rates for specifics.
Over the next few days, Google is rolling out the new feature. If it's available in your country, you'll see a little green phone icon show up at the top of your chat list (to start making calls, you'll need to install the voice and video plug-in if you haven't already). If you're a Google Apps user, your domain administrator must have Google Voice and Google Checkout enabled in the administrator control panel in order to be able to use this feature.
The search giant launched Gmail calling back in August 2010, making it possible for Americans to call any mobile phone or landline directly from Gmail. Now the feature is finally available outside of the US. As of five months ago, the company made phone numbers clickable in Gmail, thus advertising the new feature to all users who haven't tried it yet. You can start using Gmail calling on Windows, Mac, or Linux by navigating to Google.com/Chat/Voice.
Before 2010 was over, Google extended free calling to all of the US and Canada until December 31, 11:59PM 2011. We recommend you take advantage before Google starts charging you next year.