Almost a year after Google Gmail calls to mobile and landline phone were introduced, the web giant is offering its users in more countries («in new 38 languages») an opportunity to call directly from the e-mail box to people on off-line phones. In addition to this, Google has lowered the cost of the service to over 150 countries around the globe.

Voice calling to regular phones via Gmail was introduced last August as an alternative to Skype (which has introduced its iPad application yesterday). The new expanded feature will be available in every user’s Gmail account in case voice calling is available in the country—the service gets activated when there’ll be a green icon on the left at the top of the chat list.

The price of the calls is also reduced (and users pay only for the time they talk, not for the connection), while the calls within Canada and the U.S. will remain free until the end of 2011 and call to these countries from outside locations will be priced $0.01 per minute (or €0.01, £0.01, C$0.01 per minute). Here’s how Google product manager Pierre Lebeau explains the new rates in the post on Google Blog, “For example, it’s now only $0.10 (or €0.08) per minute to call mobile phones in the U.K., France or Germany (landlines are $0.02/min), $0.15/minute to call mobile phones in Mexico and $0.02/min to call any phone number in China and India.” To make a call, users can use a calling credit in four currencies (Euros, British pounds, Canadian dollars or U.S. dollars).

Twitter also deepens its global presence by translating its services into more languages. The micro-blogging service is inviting volunteers to contribute to the site’s localization efforts. Now, they are looking for translators in: Dutch, Filipino, French, German, Indonesian, Italian, Japanese, Korean, Malay, Portuguese (Brazil), Russian, Spanish, and Turkish, and if you want to help, follow this link. “Volunteers translate twitter.com, support pages, desktop and mobile applications—everything except the Tweets. Then, a select group of the most active translators work closely with the team at Twitter to maintain localized versions of the service,” says Twitter Blog.