Max Schein LED Keychain Light - $2 @ King Of Knives
Good buy for $2 since it's branded and quite good build quality.
The King Of Knives website still have them at $9.99, but the details page came up with errors so I could not link.
Here's some of the specs from the packaging:
White LED, Ultra-Bright Micro Light.
3-Year Lithium Batteries
10,000 hour Bulb Life
Visible from 1 Mile away ? (Perhaps by Superman)
15 Hours Constant light per battery set
Not sure if the batteries are replaceable but the case has tiny screws which I didn't try opening.
at $2 can't really complain, would make a good stocking filler for next X'mas too.
They still had heaps of stock there.