These are seven SIP providers given to me by Time Warner Cable Business Class (Texas) in Q1 of 2011.  I’m pretty sure that at least one of them is already out of business in Q2 with not forwarding address.

http://www.usnet-1.com/
http://www.miraclewire.net/
http://new.actsgroup.net/index.php
http://www.teamlogicit.com/
http://www.htgtechs.com/
http://www.newworldcomm.com/page/page/2056064.htm
http://www.eipsolutions.net/