XFace is an informal system to include a small (48x48x1) image in your mail or newsgroup posts.
See these links for more info... or just google it, you lazy sod!
- creator of X-face: http://www.syseng.anu.edu.au/~jaa/
- some examples: http://www.xs4all.nl/~ace/X-Faces/
- X-Face converter: http://www.dairiki.org/xface/xface.php
The quite horrid Face header has been proposed as a replacement...