Jaxtr is a very cool alternative to the existing Web-based calling services like Skype. From Yahoo! News:
Once registered on Jaxtr's site, a user can embed an interactive phone feature into selected blogs or social network profiles [hopefully the Six Apart family of blogging apps will get in on this one.]
Consumers will be able to click on any Jaxtr link, enter their own phone number, which triggers an instant call to their phone. Answering the phone connects the caller to the Jaxtr user's own phone. Callers then speak phone to phone.
Jaxtr, a play on the phrase "jack your phone," promises its users can hear from callers through their Web site profiles while preserving the privacy of their existing phone numbers.
The service provides local phone numbers that allow callers to eliminate expensive international long distance charges from any of 29 national markets in Europe, the Americas and Asia.