How to do video streaming from the N800 built-in webcam to a Linux PC if you don't have a fixed IP address for the home DSL router?

Sometimes the Internet Provider change the home IP address of the DSL router (not often though) , how do we overcome this if we don't have a server for the tablet send its IP to?
At the same time we don't know what the IP of the Linux PC at the time we are going to use it!

I am thinking we can have a script so the tablet can send email every hour or so to update its IP and the Linux PC can send back (by ???) to establish 2 way communication so we can have the streaming happened.

Any guru out there has some ideas? I think it would be a cool app if we can develop this...

Or maybe we already have one, please point me to it!

Thanks!