I hate CAPTCHAs. I know they're an effective way of fooling the form filling bots but they slow down surfing and are often very hard to read.
Now however, there's reCAPTCHA
reCAPTCHA: Stop Spam, Read Books a service that sends out hard to read words from old books and articles that OCR has trouble with and uses the results to digitize the original work.
I think that's a brilliant idea because it serves two useful purposes in one go and with that in mind I'm less likely to complain about them. I may even use them instead of hand filtering the junk that comes from my various forms.
Anyone had any experience using them?