Ok so before I get started let me just say that the reason I call it a nightlight is because it looks the best in the dark. Also the red looks a lot better in real life versus the photo. You can wire more LEDs together to provide better lighting so you can use it during the day. Now lets get started with supplies and tools.
See step 3 for update.
Step 1: Supplies & Tools
Scissors (They don't need to be very sharp)
Dremel (with bit shown in picture)
Sand Paper 100 grit
Krylon Frosted Glass Spray paint
Glass coke bottle
3ft 18 gauge wire
At least one of the following LEDS: 3.7V Blue 2600 mcd 5mm 1.7V Red 3000mcd 5mm ??V White ≈2000mcd 5mm (you can find these at radio shack amount of LEDs needed depends on when you use it) (You only should need one if you use it at night)
Flux Core Tin-Lead Solder
9V battery clips (radio shack)
3 1k Ohm resistors (you really do need these and can find them at radio shack)
Step 2: Preping The Bottle
There are two main types of labels Coka-Cola uses, paper and ceramic. It shouldn't be that hard to tell which one you have. If you have the ceramic version then use a Dremel with a sanding bit on low power to sand it off. After that's done scuff up the bottle with your sand paper. Finally, follow the directions on the paint can to frost your bottle.
Step 3: Circuitry and Soldering
Like I said this is a good project for people who have little to no experience soldering (like me!). Having a friend to hold wires for you is very helpful. Try to keep the wires as short as possible so you can just set the battery on top of the bottle and not have to have stuff dangling off the sides.
**UPDATE*** I also had a spare Nuka-Quantum cap lying around so if you have one of those you can drill holes into it and end up with the next picture.