For example you can use a service like http://www.afraid.org to register a
sub domain for free that points to your home IP address. On your home
firewall you can setup a rule to allow 5070 inbound and create a network
address translation. This will allow you to use any wireless device with a
SIP client to connect to your home computer running the MJMD5 proxy and make
free calls.

Fwd: hey hey hey.