I Roll 20's

http://www.makerbot.com/blog/2011/09/29/openscad-challenge-regular-icosahedron/

It didn't take me too many lines of code, but I did use two libraries so make of it what you will. ;)

BTW, just because it's OpenSCAD code, don't assume it's 100% parametric. It's pretty close though, someone just needs to come around and iron out the formulas.

Uses:
WilliamAAdams's Platonic Solids: http://www.thingiverse.com/thing:10725
Tony Buser's Bitmap module: http://www.thingiverse.com/thing:2054

Update
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For extra geek factor, I've included some options with some fantasy fonts. There's even an elvish option! All the text, except for the blocky original, was created with my own text2surface.py (http://www.thingiverse.com/thing:10404) with commands like:
./text2surface.py -t 20 -f "Tengwar Annatar" -z 7 -rn -d 12 -o 20_tengwarannatar.stl

Update2
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Positioned for printing.