How can I get my bacon flatter?
This is how I cook bacon, and also produce almost perfectly flat bacon. No special tools required (Well, I'm assuming most people have the following in their kitchen).

Tools


Sheet Tray
Cooling Rack (slightly smaller than the sheet tray)
parchment paper (Optional, but makes for easier cleanup).
BACON (I like the extra-thick cut).


Steps


Take the sheet tray and line with parchment paper.
Lay bacon down on parchment paper. You can fill the tray up, but I make sure the bacon stays in a single layer with no overlapping.
Place the cooling rack upside down onto the bacon. This should keep it from curling.
Place into oven and turn oven to 400 F. I don't find I need to pre-heat it, as, well, bacon isn't very complicated to cook.
In about 15 minutes or so, you'll have cooked, flat bacon. (Adjust cooking time depending on your preference of crispiness.
Take out of oven and remove from tray. (The tray and fat are hot, the bacon will keep cooking if you don't)


The cooling rack should keep it from curling while the fat slowly renders out. As a bonus, I don't need to clean my stove after.

Alternatively, the mention of the George Forman grill reminds me of an idea I saw somewhere (might have been Good Eats), use a waffle Iron! Use it just like the grill in Ward's answer.