Short one this time:
print( string.char( 0xe2, 0x98, 0x83 ) )
If you have a console that supports UTF-8, you'll see a barely recognizable glyph of a snowman. If you don't, here's what you're missing.
(happens to be my second-favorite website of all time, behind this one)
The handiness of this for roguelike development is plain. There's a good character list (with hex codes) here.