Okay, the bright white flickering LED on the dev board doesn't look that impressive. I've been experimenting tonight with different materials to diffuse the light and a yellow LED. It looks similar to a flickering candle. I found that a spare NyQuil-like measuring cap diffuses the light nicely although I want something a bit longer.

I just tried some wax paper rolled into a cylinder. It doesn't look half-bad but it's a bit flimsy.

UPDATE: I just added a photo of my experimentation of using wax paper to diffuse the light from a yellow LED.