Need to ride at night once in a while? Don't want to spend big bucks for a bike specific headlight? This instructable is for you!
Step 1: Here's what you need
A bike helmet. Riding without one is silly, riding in the dark without one doubly so! I like having a light on my helmet because it points where I am looking and can be pointed at drivers on cross streets at intersections. Get a helmet that fits you properly and make sure the straps are adjusted to keep it in place if you go down. A helmet that doesn't stay put when you crash is as bad a no helmet at all!
I like my Giro for the good buckle/strap system and the ventilation. You can get good helmets cheaply by buying last year's model closeouts at places like Nashbar, Pricepoint, etc.
Just about any helmet will work- almost all have plenty of vent holes- you'll see why that is important in a minute...
The other things you need are a flashlight- this thing is going to be on your head, so a small one is best. I used a "River Rock" flashlight that I bought at target for $20. It uses two AA batteries, it's weather proof and VERY bright. A pair of alkaline batteries will give full output for 4-5 hours. Rechargeable NiMH will provide full output for 2-3 hours. That's plenty for most bike commutes in the dark.
Oh yeah, you'll need a couple rubber bands too. I used whatever I had around. Just make sure they'll fit...