Right, I just remembered about the MagicJack. From what I understand it seems to be a service, rather than a product, isn't it? And it also won't work without an Internet connection.
That's an interesting read by the way. Pretty damn good for a "weekend project" :)
it's both. it's a hardware device with an rj-11 (normal modular phone) jack and a basic line simulator that lets you make calls using SIP. there's also a (pretty cheap) service that is billed fairly infrequently. alternatively, you can use asterisk with the magicjack device; quick googling around shows that people have figured out what's necessary to get the two working together.
the downside is that it's not wireless, so you need a separate device speaking USB either way..
That's an interesting read by the way. Pretty damn good for a "weekend project" :)