captcha in registration

[dodopek]

I need a plug-in, which use captcha at the registration. If it does
not exist, please give me an useful advice, how can I prohibit the
robots, when they try to register. No, the confirmation letter about
the registration - sended to the admins - is not enough.
Thank you for the help,
Your sincerely,
Dodopek

[Fabricio Ferrero]

Something like this?: Captcha (Visual Confirmation) for comments/registration/reporting/login/ecard