If a slow cooker uses so much less energy than a conventional cooker...

[Scootergrrrl]

Is the same true of a George Foreman grill-thingy? Is it better for the environment to use that rather than the oven?

Somebody must know!

i dont think so... i would guess it would use energy in a similar way to a toaster or an iron and they use LOADS of electricty per unit ot time

The George Foreman grill would be much cheaper than the oven as you aren't heating up all that space, just the food and the grill. A microwave is the cheapest as then the heat goes directly into the food, not the oven.