Voila, a remote temperature sensing device that only needs to be in range of the wi-fi access point to serve live temperature data out over the Internet.
The only problem I'm having is setting up the D-Link router to give external access to the RaspberryPi server. I can test everything okay using the internal IP address of the RPi, which I have made static, but until I figure this one out, I can't read the data from Ulan Batur, Tomsk or Easter Island.
I have also managed to get the No-Ip client working in Linux and have a domain name set up so it would be nice to be able to go to my domain, click on a 'Home Temperature' link and see live data. I'll get there eventually.