For a long time have I been looking for a way to see how much actual wattage my house was using and how much watt my solar panels were actually yielding at that moment.

And this is the one that I have selected and I must say I like it very much.

Currentcosts [Amazon]

Why I like it:

1. It is accurate because of the clamp for measurements
2. Nice big display
3. Can connect up to 8 clamps
4. And be hooked up to a PC to "over time" measurements
5. Allowed me to see the actual yield of my solar panels

Other devices that I have found were:

Wattcher

Plugwise

EcoWatt

Per plug in device measurement is also posible of course to find the ones that bleed badly.... Energy 3000 voltcraft

Also nice for the more social networking inclined:

Tweet a watt