TCP connection over GPRS between Openmoko and Notebook

[Michael Tansella]

Hi,

How can I establish a communication connection (I want to transfer Text) from 

A:
Freerunner
GPRS Vodafone Germany Connection (IP behind NAT)
Qt program that sends for example coordinates 

to

B:
Linux Notebook
GPRS Vodafone Germany Connection (IP behind NAT)
Qt program that processes the received Data immediately

I want to implement this in a QT4 program and thought about TCP
but how can I get a "global" accessable IP address.
Does there already exist any tool that can do this?
Do I have to use SSH, VPN, HTTP, FTP, ...? Unfortunately I don't know much 
about networking stuff such as NAT etc. , can you just give me a hint, how to 
start?

Greets
Michael