The only way I know of is to use a VoIP service provider - many of which are mentioned in posts above. To be able to call a landline you need to pay for the service - all the free services (like skype) are only free when you connect to another computer user through the internet. However, if you pay for the service (including paying skype either per minute or by subscription) you can not only call landlines and cell phones, but you can get your own landline number as well.
The service I use for my business provides me with a landline number, a fax number, and 2000 free minutes per month of calls to practically any landline in the world. The landline and fax numbers are normal local numbers that they ported to the VoIP service for me from my previous conventional phone company. Using these types of services you can have your own local phone numbers any where in the world, and have them all come to a headset on your computer, a dedicated VoIP phone, redirected to a landline or cell phone anywhere else in the world, or any combination thereof.
- However, as far as I'm aware, you can only use VoIP to call a landline if you pay...
