I'm very familiar with CAPTCHA images from a user's point of view, but now that I am going to need to use quite a few contact forms in the future, I'd like to know how to actually implement it. I'm familiar with HTML/XHTML, CSS, and I can understand PHP, but I don't know where to start with CAPTCHA. Any help?

Thanks in advance!

~anwipr

anybody? again, thanks for any help!

http://www.codewalkers.com/c/a/Misce...TCHA-with-PHP/

start with a tutorial like that. 'Php captcha' or 'php captcha tutorial' will turn up an overwhelming amount of results on google if you don't care much for that particular one.

Try a tutorial and post back if you have any particular problems. Good luck!

There's an easy way. A way in which you can have captcha in your page and help digitize old books. Its called reCaptcha. With this system, you are given a twisty word from some old book and when you type it correctly, you translate one word for the whole world.

Here's what they say about it :

About 60 million CAPTCHAs are solved by humans around the world every day. In each case, roughly ten seconds of human time are being spent. Individually, that's not a lot of time, but in aggregate these little puzzles consume more than 150,000 hours of work each day. What if we could make positive use of this human effort? reCAPTCHA does exactly that by channeling the effort spent solving CAPTCHAs online into "reading" books.

Try it. Make a positive contribution to the world .

@bhgchris: Thanks, that tutorial looks simple enough, I would say I'll save it for a rainy day, but that's today, so I'll give it a try later.

@astrojith: Yeah, I actually saw that a while ago and it sounded great - I might try to use it in the future for something, but I want something a little bit less (for lack of a better word) obtrusive for the form I'm thinking of right now.