Similar to South Park Studio's Create-A-Character, this little Flash avatar creator (from an unknown author) is a bit more versatile and has a few more options. Create a face of your own that fits your unique personality, then do a PrintScrn and paste into your favorite bitmap graphics program. For a larger face...
Update: Thanks to Dave for reminding me about Mr. Picasso Head, another fine interactive Flash art 'game'.
Note: If you know who created this little gem, please let me know so I can give proper credit and also contact the author. Cheers!