Hi! I've just finished my new graphic CAPTCHA engine. It's quite simple and innovative (at least I hope so). The most interesting fact here, is that it would hardly be possible to make it without such powerful HPC programming technique as OpenCL (and, of' course, AMD GPUs). I don't know if URLs are prohibited here, but you can email me for it, or just search the web for "gestcha" (with ".com" may be ). Take a look and tell me your opinion, please!