Asterisk, Voip and IP Telephony.

I’ve spent the weekend playing with some VoIP technologies, in the hopes that eventually I’ll be able to fully automate my home telephone system. It all started a while back when I obtained a “BT Voyager 10V” combined, router, VoIP, hub type thing..  ( I use the term Thing loosely here.. ) and being the type of person I am, I thought why should i be tied to only using this thing with BT?