Is the Arduino Alive?

Now that I have the required components to build my prototype, I have been playing around with lighting different LED's using different Resistor's and powering the Arduino through the USB port of my Mac.. So far, so good... I have managed to create a successful circuit that lights the LED. I have tried testing it out with more and more LED's, however it seem the inevitable has occurred...! The LED's seem to dim the more I ad, which I guess is due to the power source being the computer and only limited to 5V. This may only be enough to power one LED... Which is not exactly what I had planned! I will try some other options, maybe Less powerful LED's so as to include more than one, either way, I do not want to include an external power device for the gadget as this would mean having to compromise the final size of the device. As I  am not running physical sensors in my circuit, it makes so much more sense to try and get the most out of the USB port's power.

FINAL VERDICT; Yes.. the power LED comes on when the Arduino is connected, and the LED on my bread board is lighting up...