This is my first Instructable, so bare with me if pictures are in the wrong places...
By the end of this instructable you will have a little glowing lego man that you can plug into your computer

You will need:
Lego man
LED
Thin wire with and without plastic coating
Connector Block
An old/unused USB cable
Insulation tape
Superglue

As for tools,
Soldering iron (with solder, duh)
Pliers
Wire Cutters/Strippers
Scalpel/Sharp Knife
File
Very fine Drill (Needle type),
Drill the same size as your LED (~5mm)
Hacksaw

There, you never thought you'd see the end of that list did you...

Step 1: Dissect Your LEGO Man

Hopefully you are like me and have a large amount of these LEGO men which can be used for all sorts of things.
First off, take him completely apart, arms off, legs off, head and torso off ... etc.
I drilled his eyes out first, using a very fine 1.5mm drill bit at a slow speed. Be careful here as the bits snap easily as do the heads...
Next we will cut his neck off, using the hacksaw, then drill it out so that more light gets through.
Make sure you've got his legs separate to the hips, you may need to use a flat blade screwdriver to do this.
Drill another fine hole through the top of the hip on each side, then using the hacksaw, cut a small slit in the top of the leg. This allows him to be seated even with wires running down his legs. Drill through the middle bit inside his legs too.
Finally, bore out the inside of his torso using a 5~6mm drill. Use a file as well to clean up and rough edges.
Superglue the head onto the body, but leave the legs off for now.

Step 2: Fixing Up Illumination

Yes, it's time to get the lighting ready.
Solder some completely stripped off wire wigh up the terminals of the LED, and snip off the rest of the LED terminal. If you do it lower down, the soldered joint will not fit through the slits and holes in his legs...
Test the bulb using a small battery after each solder, to check you haven't burnt it out and that the connections work.
Run the bulb wires down the legs, remembering which is positive and which is negative - on your LED, the longer terminal is usually positive. I made sure the positive wire always ran down the right hand side.
The bulb should fit snugly into the torso, and the legs should reattach like normal.

For the USB side of things, cut off the device end NOT the USB plug! Strip back the shielding and chop off the green and white, but leave the red and black. strip the ends of the red and black and screw them into your block.insulate the cables and tape it up. I used the block so that I can easily add more men to the power, or use the cable for other projects - much better than soldering.
Finally wire in your man, and check NOTHING is touching - if it is you risk melting your motherboard - I have seen this happen on a customers PC which had shorted the USB and it almost caught fire!

Step 3: Light Me Up!

Give it a final check for shorts, and then plug in your USB!
Watch as your little man lights up. Try different ways of securing him, using other bricks, plasticine, glue etc...

Enjoy!

Sorry about the poor pictures, I used my phone as I couldn't be bothered to charge my camera.