Spam Prevention/Reduction - Contact Form?

Question

I want to add a simple Contact form to my web site so that customers can contact me easily.

<form>
    NAME
    <input type='text' name='name' />
    EMAIL
    <input type='text' name='email' />
    MESSAGE
    <textarea name='message' />
    <input type='submit' />
</form>

This form would simply email me the customers message.

But, I also want to reduce (not, I'm not saying eliminate but at least reduce), SPAM.

I've looked into using CAPTCHAs but, ultimately, I don't want to hinder the customer with having to fill out extra information.

Any ideas of a good simple spam prevention/reduction method I could use for my Contact form.

Answer 1

A very simple trick I've been using with a surprisingly good success rate is this: Provide a text field that is hidden from human users with style="display: none", but with an enticing name like email. Most bots will fill in something in this field, but humans can't see it so they wont. At the server, just make sure the field is empty, else treat the submission as spam.