I find many Captcha images very difficult to read. I dread finding a Captcha box. I've heard that from several people so it's not just me. I saw a forum posting requirement with a very simple Captcha-like requirement. Text was to put in the numerical answer to a very simple equation like 2+2= . You got one more chance to answer.
I definitely liked that idea. Is it effective? What about something similar like requiring a certain radio button or checkboxes to be checked?
I'd suggest that you take a look at the myriad of PHP classes dealing with Captcha options at phpclasses.org. You'll find something you like there.
An example of this is new today:
Note, please that this is not an endorsement of this particular class but the latest example of the CAPTCHA classes offered by phpclasses.org.
There was a very recent discussion of Captcha and alternatives in this thread, which you might find helpful.
Thank you for the replies. I do have to learn php so I will start at phpclasses. A fun thread that was TechnoBear and helpful ideas for what does/doesn't work and why.