TraderZones has given you a good answer. I have a dry copper pair (no dial tone or phone) from AT&T on which runs my DSL . I use a good hardwired switch/firewall that routes to all the PCs. Buy a Majic Jack @ Wal Mart (I have 3 which are routed into a PBX for the house), connect it to a USB on your laptop, download the software. Connect any old hardwired or wireless phone to it and make all the calls you want. I can even Fax thru my setup. OR Wireless NIC and surf your neighbors connection with his permission and use Your Magic Jack setup.
Comcast has been wanting to sell me their Xfinity package - Cable TV, cable modem (internet), and VoIP phone - all in one. To replace my AT&T dial tone. Everytime, I stop them cold. No way! With the crappy reliability from Comcast... everytime my cable signal gets interrupted (no internet), I will be out of phone service as well? Something to consider when you put all eggs in one basket.
internet-based phone sucks unless you have 100% reliable internet, which NO ONE has. out of the three voice services (internet-based, cellular, and landline), the latter is still the most reliable. landline is very mature technology so all the kinks have been worked out. you can't say the same about the internet or cell phones. i used all 3 for voice calls, and only landline is acceptable nearly 100% of the time