image-only spam -- ideas, what to do?

[Francois Visconte]

Hello

>I'm impressed by how much doesn't get through. Bogofilter is currently
>picking up around 86%-87% of the spam I receive - and that's using the
>default parameters. 
>
I'm using default parameters too and 99% spam detected since 2 weeks

>Every so often I get a burst of spam that it
>doesn't pick up, but it learns pretty fast and they soon get dumped
>liked the rest. I'm thinking of tightening it up so that it picks up
>about 95% (any more and I'd worry about losing ham), but in general I
>find I can relax and let it do its work.
>
>I was impressed by SpamBayes, which I use on my other PC, but
>bogofilter is even better,
>  
>
Even better than spamassasin (i was using before) and the most important 
point to me, low resource consumption.
I use this procedure to make bogofilter learning spam 
http://fv.kh3.org/doku.php?id=sysadm:spamfighting.
Is anyone has any improvment for that ? It's quite efficient right now 
but i'm searching for other techniques of spam-learning.

Best regards,
François Visconte