The LED Nametag is the perfect kit for that next meetup.
It comes with 4 built-in programs: all on, letter chase, fade, and blink. There's also a power saving mode.
The kit is pretty easy to build. It's all "through-hole" parts, and besides the LEDs (which do take some time), there are only 4 other components that need to be soldered. Check out the build instructions for an idea of what's involved.
Here's a more in-depth video and walkthrough of the kits:
The code is open source and you can reprogram the nametag by adding an ISP header.
The LED layout is pretty simple. It's 20 columns across and 5 rows down. It's sub-divided into blocks of 4 columns by 5 rows. This is the most granular control (and used by the letter chase effect). The kit works best with 5 letter or smaller names.
If you come up with another interesting font, symbols, icons, etc. please let us know!