I want to move the phone line in my apartment to the Black/Yellow pair, leaving all my phones on the Red/Green pair, and then put this in the middle. Then I want to setup a database where all my friends (who do the same thing) can publish their phone numbers along with their IP addresses. When I pick up my phone the dial tone will come from my computer. I dial a number, and it does a lookup on the database, and if the number is in the database it routes my call over the internet, otherwise it uses pots... All the voip, no monthly fee. Hellz Yeah!

Asterisk - The Open Source Linux PBX