验证码是否足以强制执行多次失败的登录尝试？

Before I go crazy and try to script a way to lock folks out of their accounts on multiple failed attempts, is a captcha ideal? I've seen several sites that do this, but wasn't sure how effective it would be. Granted, if a human is indeed trying to "hack" into someone else's account, I would think blocking access for a few minnutes would be much better than having them input some random obscure characters.Before I go crazy and try to script a way to lo