Looking for an anti-spam solution easier to implement than Captcha

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开发者_如何学运维'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?

you can add an additional textfield to your form and hide it with css. human users don't see the field, so it should always be empty. spambots usually fill out all form fields and don't know that this one is hidden. if you receive any content in this field, reject the form submission.

Put up something like "What is 3 plus 6?" and give the user a form to type the answer. Any human will get that, including blind ones who can't see a captcha, but no bot will. You don't even need to vary the numbers, really.