I just read this article about a kid in England who built a box with a
3G SIM card:
When someone rings your intercom, the box will call your cellphone so
you can answer just like you were home.
I don’t know anything about electronics and would like to have
something similar by connecting the intercom end in my appartment to a
PC running Asterisk that will dial a phone number through SIP.
Does someone know if something like that is available ready to use