Every year we build a LED suit for Halloween. Last year we did a quick low LED count Iron Man suit that played with the surrounding music using a microphone - ah to be 12 again. It was a great test - the microphone did great and so did the battery setup. So this year we plan to build a suit with 100 LEDs. I'll post updates here as to the progress.
Below is a video of this years suit helmet and chest plate- 44 out of 100 complete :).
Nice work. You're definitely not going to be hit by a car while you're trick or treating 
Would you be willing to share the sketch your running? Very very cool setup!
And a schematic of the circuit?
The sketch can not be posted for copyright reasons and there is no circuit to share. That said I can provide details that should allow you to recreate something very similar.
The LEDs are 5050 style with built in WS2801 chip.
Form factor is like this but with WS2801 chip.
http://www.bliptronics.com/item.aspx?ItemID=98
For music control on board - I use this.
Here is a library to control any of the above mentioned LEDs.
http://code.google.com/p/fastspi/
Hope that helps.
Project Update:
We finished the main body including shoulder spikes and added detachable arm pieces. Here is a video showing the new additions along with more details on the physical suit build.
We purchased some 5v power adapters made to charge cell phones. Since they handle 1.2 amps each - I got 4 of them to run the 70 RGBs in the suit. The concept worked well and has proven effective.
We also added the spectrum analyzer shield and microphone setup and tested it with ambient music (from a small self powered speaker).
Here is an updated video showing this years Halloween costume suit with these updates.
One month until Halloween - maybe time to give this robot some pants 
Ya had me droolin till you said copyright and no schematics.. To each their own, I guess.. But Arduino is all about open and sharing.. Is that even controlled by an Arduino? Doubt it.
I don't think you really need a schematic that shows pin 11, pin 13 and ground wires being plugged in. In fact in this post I provided you this exact detail in december of 2010 including a link to the library.
In the above links and videos I provided ...
The LEDs are 5050 style with built in WS2801 chip.
Form factor is like this but with WS2801 chip.
http://www.bliptronics.com/item.aspx?ItemID=98
For music control on board - I use this.
Here is a library to control any of the above mentioned LEDs.
http://code.google.com/p/fastspi/
A complete video with close up on the LEDs and full details on the build.
Complete details on how to power 70 LEDs on a craftsman tool 12v battery.
Just because I don't provide the 4 libraries and multiple applications on the PC and the arduino it takes to pull this off you tell me I am not "sharing". It would take way more than I can document to understand what it takes to pull this off, sorry.
If you try to get this working and need help - ask specific questions. Don't ask "give me everything".
Best of luck.
Fair enough, I understand now. Sorry if I was a bit harsh.
Here are some videos of the final suit. We added a belt, legs and a wii classic controller.
Suit, patterns and control overview:
Here are some videos of music play.
Suit Responding To Piano Music:
Suit Responding To Techno Music:
Happy Halloween!