But you know those crappy 3 led flashlights they give out everywhere?
Take one of those apart to make it more compact.
Yes, my camera is broken so the pictures are minimal.... meaning I have 2 of them
Step 1: Get Your Stuff
1 roll of trusty teal duct tape
1 mutilated led flashlight
1 momentary pushbutton switch (not shown, can be a homemade switch)
Step 2: Put It Together
Tape the LED down
Tape the momentary pushbutton switch to the other side of the batteries.
Wrap in your favorate color of tape
Push the button to operate, release to stop.
Wasn't that easy? and now instead of a stupid plastic case, you have TEAL DUCT TAPE!!!!!
Pushbutton not shown in picture.