RGB LED spheres controlled via MAX or OSC device

So, I want 5-10 spheres with RGB LEDs inside. Each sphere's LEDs will be doing the exact same thing (2-4 LEDs per sphere), but each separate sphere will have the ability to do different things than the other spheres, in terms of lighting up, what colors, etc. I'm making a central control software that will translate input to serial values. So the part I'm curious about:

I imagine it working like this: Central Arduino accepts input from MAX MSP, then sends out data to each sphere, which has an ATtiny inside. The chip parses the number received and splits it into R/G/B values, and PWM's the lights accordingly. I don't really want to use those complicated LED controller chips if I can do it with "normal" chips programmable via Arduino. So as far as the output from the central Arduino, how do you send serial to multiple devices? Is it possible? Help :)

Thx, me

It sounds like what you want is a shftbrite http://macetech.com/store/index.php?main_page=product_info&products_id=1

How big are the spheres, how far apart are they, and how bright do they need to be?

If, for example, you are suspending these from the ceiling so they're mostly viewed from the sides and bottom, I find that wide angle LEDs at one side of the sphere light it up pretty well.

If these are more than a couple feet apart, any logic-level communication will be problematic. You would likely want to have a central controller with just the LED power wires leading to each sphere.

They need to be very bright. The shiftbrite sounds good, but it's only a single LED and I want more power. Can one solder more to it?