I've bought a flukso v2b, a device meant to monitor the usage of electricity and gas. I simply hooked it up to the P1-port of the Smart Meter, and it worked. It came with the right cable, it just had to be connected in reverse. I love the device, the graphs I can see on the website (http://www.flukso.net) are fine, but of course I had to tinker. I aimed for a way to see the current power-usage, the consumption per day and per month. The website offers almost just that, but there's no way to see your month's usage. And I love to tinker, so here we go !