寻找比Captcha更容易实现的反垃圾邮件解决方案

I'm looking for a simple anti spam form submission solution, other than Captcha. I've tried implementing Captcha into my website for anti-spam purposes, but it's been too difficult to integrate into the site. I don't get many spam attacks but I'd like to have something in place for the random spam that I get. Does anyone know of something they think would work?I'm looking for a simple anti spam form submiss