This is a software and hardware interfacing question, but I am going to start with the hardware first.
I am using the bliptronic (lpd6803) leds in my project.
Looking at bliptronic's example code the timer simulates a single clock cycle, correct? That means the LEDs are getting updated rather slowly. Then I found the fast spi library for them. However, I am already using an SPI device with cable select in my project. So that means I would have to add a CS - also modify the library to use it, but that is the next step.
To add CS to the LEDs would it be as simple as to hook up a transistor to the the CS pin and between the MOSI arduino pin and data pin on the LEDs? Or does it need to be a relay?http://code.google.com/p/fastspi/