Skype is huge in Poland

The top five countries of Skype penetration according to this article (dated February, 2005) are US, Poland, Germany, France, and Brazil.

Now things get even better. SkypeIn, a service that lets you receive regular phone calls on your computer, provides numbers based in Poland (at the moment from the Warsaw area only). The service is still in beta and there are only 8 countries from which you can have a number.