Ever since its debut in August 2003 Skype has seen tremendous growth in the consumer market. According to the company, which boasts an estimated 300 million registered user accounts worldwide, its users logged 14.2 billion minutes of computer-to-computer call time during Q1 of 2008. And if the company’s first monthly package offering unlimited overseas calls proves successful, its usage is about to grow much more.

Starting today, customers will be able to buy a “World Unlimited” plan to make unlimited calls to landlines in 34 countries – including most of Europe, as well as Australia, Canada, Chile, Singapore, and China for $9.95 per month. Each subscription also includes a Skype to go number, which lets users make international calls at local rates from a cell phone or landline phone. For those who regularly do business with people overseas, this could make a great, inexpensive calling plan for their needs.

Other plans are also available, including unlimited calls to landline and cell phones in the U.S. and Canada for just $2.95 per month, and unlimited calling to Mexico for $5.95. The new plans are available now, and Skype will offer a 33 percent discount on 3- and 12-month subscriptions through June 1.