Captcha workaround while using a text only broswer

Solution 1:

I think that in text only webbrowser it would be much easier to use "audio" captchas, sometimes described as "for handicap users".

Solution 2:

Update:

For those who read the question as "As a webmaster, what can I use as a text based alternative to CAPTCHA?" please read my original answer -- however it seems that the OP actually meant "As a user, how can I convert CAPTCHA images to a text representation?".

To answer the later, I'd say that this is not really feasible with ASCII art, unless you were willing to use the entire screen, since you'd need this kind of "resolution". If it's a website that people commonly browse using lynx, then you could contact the webmaster and ask them to solve the problem ;-) -- I was going to suggest wgeting the image and using an ASCII art generator, but then I realised that it'd most likely change each time it's downloaded.

Original answer:

Ask the user a simple math question; what is 1 + 2? This will protect you against generic spam bots (of which there are many), but not targeted attacks (of which there are few). However, ASCII art would be a much cooler solution.