This is my first instructable, so it is pretty straightforward and easy to make! I finished mine in an afternoon! *EDIT* I have entered this into the make it glow contest, so if you like it don't forget to vote!*

Step 1: You Will Need:

.A funky bottle
.a 5mm super bright LED
.Wire
.a 2AAA or 2AA battery holder with flying leads
.an SPST switch (2 prongs)
.Heatshrink tubing and/or electrical tape
.a good quality glass drill bit
.a heat source (if heatshrink is being used)
.Blue tack and Hot glue
.a soldering iron and solder
. a Sharpie (optional)
.a vice
.A drill
.A glass of water
.Wire cutters
.Wire strippers
.Heatproof mat (optional)
.Helping hands (optional)

Step 2: Drill the Hole!

Put the bottle in the vice, and tighten it down so that is firm, but not so tight that the bottle is squished. Now mark where you want your hole to be with a sharpie. Next, soften your white tack and mould it into a saussage. Mould it into a circle around where you want to drill, and make sure that it is pressed firmly against the bottle. Now fill your new 'cavity' up 3/4 of the way. Now put the glass bit in your drill, and take it slow. Don't apply too much pressure to the glass or it will crack- this is also more likely to happen if you have a cheap drill bit. Make sure to take fairly regular breaks, and replace the water when it gets too cloudy. When the hole is drilled, check the fit of the LED.

Step 3: On to the Electronics!

Get your electronic-y things out (check the picture) and plug in your iron to heat up. It is a simple circuit, and pretty much anyone with any knowledge of electronics can complete it- The schematic will be in the pictures. It is now just a case of putting heatshrink on your components ans soldering them together. Dont forget to tin yhe ends of your wires, as it will make them much easier to solder to. The only extra piece of wire you will need will be from the 2nd prong of the switch to the negative lead on the LED. Just follow the pictures.
When you are done, test the circuit and you are ready to move onto the final step!

Step 4: Mounting!

When the circuit is complete, it is time to mount it into the bottle. Put the LED in the hole and cover it with white tack or hot glue, and then position the switch where you want it and white tack/hot glue it in place. I found that the white tack didn't do a great job of holding the switch in place, so I actually ended up hot glueing it in place. When the main components are mounted, it is time for the battery pack. Simply put a velcro hook at each end of the back of the battery pack, and then stick the loop side to the hook side, so the adhesive is showing at the back. Now stick rt wherever on the bottle you please!

Step 5: FINISHED!!!

You now have a completed bottle light! You could of course experiment with different coloured LEDs, for a different effect, but I chose white as it is a more versatile colour. Now, show it off to your friends and family!!
ENJOY!