I've been screwing around with this for about an hour now.
http://www.glassgiant.com/ascii/

Settings I reccomend:
Maximum character width:400
Font size:small
Color scheme: Black on white.

When you get the image back in ascii, use control-minus (zoom out) a couple of times to see the full picture.

I wouldn't try posting the results here.

wow, thats pretty cool atually. I wonder how it works