spin your choice!
Obfuscation Contest -- make your program as complicated as possible
ASCII Graphics Generator
Trig Function Grapher
Spell Checker (dictionary provided)
Redo a common program in a creative way
fordy: probably stick with C/c++. maybe inline assembly...
i'm only saying this because this is a c/c++ forum, and most people here don't know other languages.
anyway, it's leaning towards text compression.