After being inspired by one of Kip Kay's how-to videos, I decided to build an LED banner for my school club SkillsUSA. I have also built another banner for Class of 2013.

Materials:
LED's
foam core
printed foam core (optional)
8 - 16 AA batteries
AA battery holder
picaxe
PCB from radioshack
4 light switches
solder

First drill out the holes where your LED's are going to go and insert all the LED's.

Solder all the negative terminals on all the LED's together and solder a 510 ohm resistor to the positive lead of each of the LED's.

connect all the other ends of all the resistors together then connect them to one pole of the light switch.

connect all the negative leads to the battery pack (8 AA batteries) and connect the other pole of the switch to the positive lead on the battery pack.

(optional) you can make a picaxe 20M blink up to 7 LED's in any way you want, but for my project I had 6 blink around the edge of the banner in a circle.with red and blue LED's. There are 6 pins that are on the microcontroller that you connect the positive of the LED's (with a resistor) to and the negative leads on the LED's go to ground, and I used a 5v regulator to power the controller. You can program the picaxe by using their free software from http://www.picaxe.com/Software and they have some tutorials on how to program the picaxe.

I built a rectangular wood frame that i could velcro the foam core to and I got a presentation foam core board and velcroed it to the back so then I can open one third of the back panel to turn it on instead of having to take the whole thing off.

Approximately 236 LED's

Also check out my Class of 2013 LED Banner