Power Source for Bicycle Light project (video)

Hello I'm seeking some help picking a power source for a project. A quick rundown: I'm designing a bicycle light system for nighttime safety that will include passive lights, turn signals, and brake lights. I am controlling 9 Bliptonic LEDs: http://www.bliptronics.com/item.aspx?ItemID=86

with a Picoduino nestled in the frame: http://themakerspace.com/testsite/index.php?main_page=product_info&cPath=1&products_id=2

I've got all the preliminary work done, here is quick demonstration: http://www.youtube.com/watch?v=e7dUXa_Sv8g

Anywho, I want to put it in the bike now but I don't know what power source to use for the project. I was thinking of connecting 3 AA batteries in series which would get me to 4.5 volts (close enough to the 5V needed for the lights yes?). Also, do I connect the power to the 5V and Ground nodes on the picoduino? Thanks!

ACK this is in the wrong board, please ignore. Reposted: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1291110140/0#0

Hey don't cross post, it pisses people off a lot round here. >:(