Step 1: Collecting Your Parts.
2: 5mm Green LED ($1.49).
3: 5mm Blue LED ($3.49).
4: Heavy-Duty 9V Snap Connectors ($2.99).
5: Female USB Type A Extension cable (choose whichever one you want. Remember: you are chopping the female USB part off anyway, so get a low quality, cheap cable).
6: VERY SMALL Slide Switch.
7: VERY SMALL Momentary push-button switch.
8: CR2032 Battery(s) 3 pack plus CR2032 battery holder(s).
9: Metal 5mm LED holder (it has nuts and bolts on it, so it can be tightened to fit nicely in the box, and it comes in a 2 pack and is for the high power blue LED), plastic LED holder (for the low power green LED, it can't be tightened, and it comes in quantities of more than one).
10: 100 ohm 1/8W 5% Carbon Film Resistor (package of 5).
11: I recommend an Altoids tin because it is a strong, sturdy, light weight tin that is only $2.50 at Seven-Eleven (as a bonus, it even comes with the tasty mints). For those of you that go to Trader Joe's, you can also use Myntz. If you don't know what Myntz are, they are just basically really strong mints that come in an almost identical box as altoids, which means the same material, size, shape, and more. The only difference is that it doesn't have an indent like the newer Altoids cans, not the older Altoids cans. I am warning you right now that if you go any smaller than this size, it is most likely not going to fit, or if it does, the tightness of the way everything is stuffed in the container will break your connections, SO DON'T DO IT! For those of you that don't have access to both of these mint containers, you can improvise. Some people use metal cans used for fishing. Get creative. You can even spray paint the box BEFORE you drill your holes and place your parts inside.
Drill and Drill bit (unless you aren't putting this in a box, or if your box already has the right sized holes)
Helping Hands (optional, but helpful, hence the name)
Wire (Red and Black)
Electrical tape or hot glue
Note: I tried using hot glue to hold together things I soldered. It didn't work. Within minutes I had a mess of glue and broken connections. When the hot glue made contact with the wire, it heated it up and disconnected it. Only use the hot glue to mount the USB and maybe the LED. Just hope the LED doesn't burn out, because then you have to break out your knife and start hacking away at the hot glue. The safe things to hot glue are the USB. Don't try to do it with the battery. Don't wonder why, JUST DON'T. Use electrical tape for everything else, IT WORKS.
If you want to, replace the 5mm Blue LED with a Blue 2600 MCD intensity, T-1-3/4 (5mm) size LED. It is $4.49, but if you want to use your second LED on this project as a real light, this is the way to go. The green LED is only a power indicator, so you want it to be fairly dull, so that every time you look at your charger, you don't have to squint. Try to by the lowest brightness power indicator LED you can find.
If you want to go even brighter, to a blinding degree, I recommend getting a blue or white 10,000 mcd LED. It will consume more battery life, but on the other hand, it will be really bright.
Step 2: Drill Your Holes.
Step 3: Test Your Circuit.
Its quick and simple.
All you have to do is create the circuit using alligator clips. This will help you know in advance if you did something wrong. If you did it right, take a picture, or draw an exact schematic, and then heat up the soldering iron and get ready to solder.
Step 4: Create Your Circuit.
You don't have to make this with 2 LED's. You can even make it with no LED's! It will just leave you feeling like you could of done more to make it better. So choose right now.
I just recommend starting off with one LED, and the way I made my circuit, the high power LED is independent. It doesn't rely on the 9v to be powering it. It has its own power source (that's what the CR2032 batteries do). It just means that you don't have to flip two switches and have the 9v powering the USB and low power LED along with the high power LED. It gives you more battery life, and less need to mess around with the original, fragile circuit. You just have to make an extremely simple circuit that connects the - of the CR2032 battery holder to the 100 ohm resistor and connect the resistor to the - of the led (the shorter wire of the LED), connect the + of the battery holder to the switch, and connect the other terminal of the switch to the LED. See, its really easy. As always, look at the pictures for help.
If you have questions, just comment, and I'll answer back.
The schematic should answer your questions.