I am using a linksys spa-3102 to connect to my pots line and another one to connect to my magic-jack. The other 2 ports on the spa-3102s go to a couple of phones. I have it working where I can dial 9 to get the pots line or dial 8 to get the magic jack, dial 7 to connect to the repeater, or dial from one phone to the other. Incoming calls ring both phones. I haven't figured out voice mail, call waiting, or anything else yet. But it is a start and most of the info came from the free asterisk book. As I learn more I want to subscribe to a voip service like
http://www.callcentric.com/dids/personal_unlimited and also interconnect with Gizmo5. Hopefully I can then get rid of my pots line and port my number over to the voip provider.