To be honest, it's because I'm really new to this and wasn't aware that the LED would need any external power.
Thanks again for your input, Groove and AWOL! I take it from your responses that I SHOULD use external power. This being said, since I need to hook up 12 of these 1 Watt LEDs, I believe I need a 12A power source. Are there other electrical implementations I should use with this--i.e. a transistor, a voltage regulator, etc.? Again, I'm really new to this, so I apologize if my questions are really elementary.