I'm looking for the best way to power a single LED and have a toggle on/off switch.  The led is in a balltop I got from Luigi (
http://www.thludwig.de/arcade/led_sticks.html)  The balltop will be in a 1 player fight stick that will probably use a 360 pad hack, so I dont want to use a led wiz or anything like that for just one LED.  I have seen people use battery packs in the past, but I'm not sure about the size/power to use and how to incorporate it.  Something similar to these ad radioshack - 

So would it be possible to power just one led from one of these battery packs?  If so would I just wire the battery pack to a toggle switch and then wire that to the 5v and ground wire from the led?  Is the a better way of doing this?