The compface's I have tried (compface RPMs and compface from 
freshmeat) doesn't seem to work, or maybe the pbmtoxbm program I 
have doesn't work.  Compface seem to want 48 lines each containing 
of 16 bit C integers, but pbmtoxbm outputs a C character array. 
pbmtox10bm (X10 bitmap format) outputs 16 bit integers but not 
three per line.  If I manually edit it to make compface happy it 
outputs the X-Face in this message, which looks corrupt.  Any 
ideas?

Using standard formats would be nice..  Converting the image below 
to a 128x128 PNG takes up 11 base64 lines, I'm sure it could be 
reduced further if someone tried.

(Or perhaps someone could convert the attached GIF for me. :-) But 
I want to make more X-Face's anyway...)