I'm building a free-standing 8x8 RGB LED matrix. Unlike the coffee-table style builds, this one will stand vertically, with light coming out both sides. I just finished wiring up the matrix and doing initial testing.
I'm using a Colorduino (http://blog.lincomatic.com/?p=109) from ITead Studio. If you're interested in following the build, I'm documenting it as I go.
8x8 RGB LED Matrix Construction: Step 1 - Cutting Foam Board: 8×8 RGB LED Matrix Construction: Step 1 – Cutting Foam Board – Lincomatic's DIY Blog
8x8 RGB LED Matrix Construction: Step 2 - Wiring: 8×8 RGB LED Matrix Construction: Step 2 – Wiring – Lincomatic's DIY Blog