The Happy Face emoticon from many web applications. I modeled this directly using the emoticon icon from Facebook. Would look nice as a pendant or a key chain. The loop is about 2 millimeter aperture and is meant for women to use with thin chains.
These are matching earrings http://shpws.me/o73F
2.54 w x
0.564 d x
1 w x
0.222 d x