halogen lights

So I'm considering replacing my lights with halogens. I am wondering if anyone on these forums has experimented with that. Do halogens use more power? Is that something I have to worry about? Will I have to extensively rewire stuff?

Last but most important of all, anyone know where I can get these? I admit I haven't looked into it too deeply yet. I think a glance into the experience of these forums will be a good place to start and then I can start calling local dealers and see what they say. A quick online search didn't yield much... Thanks guys!