It's never too early to plan your Halloween costume. Some folks like to keep it simple. With these hats, you probably won't even need the rest of the costume to draw attention. Bonus: these are all homemade, and they come with instructions for making your own.
Are we not men? Rob at Cockeyed.com made these Devo hats for a Guitar Hero party, and posted step-by-step instructions.
Check out this Chicken Viking Hat that Vicki at Knitorious made! This one may actually work better for Thanksgiving than for Halloween, but it's a conversation-starter whenever you wear it. Here are complete knitting instructions for a child size hat and an adult-sized hat. Update: Vicki made the sweater, and her friend made the hat for her. They call it the Cold Turkey hat, as they both quit smoking!
More hats, more instructions, after the jump.
Instructables has a tutorial on how to make your own disco ball visor. What kind of costume should you wear with this? It doesn't really matter, since this will reflect all attention away from the rest of you.
If you're ever going to be a balloon sculpture artist, you have to know how to make a balloon hat. Otherwise, passers-by on the street won't know you are a balloon sculpture artist! See the illlustrated tutorial here.
If you are worried about aliens trying to take over your mind with radio signals or whatever they use these days, you can construct your own Aluminum Foil Defector Beanie (tinfoil hat).
It can't be stressed enough how important it is to have the shiny side pointing out. This is needed because the shiny side is most reflective to psychotronic radiation, while the dull side can actually, in certain environmental conditions, absorb it. However, as is illustrated in the instructions above, it is also wise to complement this with a layer of foil pointing shiny side in. This will keep your brain waves, which are also reflected by the shiny side, from being picked up by mind-reading equipment.
Or, you can buy one.
The Giddyup! Pony Hood can be made with or without the kinky bit. The child size is downright adorable. Downloadable instructions are available from Naughty Needles. You'll also find a devil horn version.
The original tutorial on how to make a cat fruit helmet has disappeared from the web. Too sad. I remember it required a bottle of tequila, limes, a knife, and a very patient cat. The tequila was only for inspiration, for which you can use the above picture. You can probably figure out the rest. Your cat may be just as happy about it as this one.
Just in case nothing else you see here is at all useful or practical, here's down-to-earth instructions for making your child a witch's hat for her Halloween costume.