[jtheory]

[The ghurlman response must be a response to the OP, not this comment. This approach is perfectly accessible -- better than any captcha!]

I use the "honeypot" field trick as well, and really like it, but this approach has some problems worth mentioning.

For one, make sure you give real users a way to contact you if they somehow get trapped -- you'd think it won't happen, but have you tested every available form-filler plugin out there? A few months ago Google released a new version of Chrome that started putting email addresses into my hidden field. Maybe Chrome thought it was a "confirm your email" field? No idea; I fixed the problem by adding an HTML label for it. But it's a damned good thing I wasn't just secretly discarding the input, or I'd have lost a lot of purchases.

Next, as you mentioned, if anyone targets you specifically, it's trivial to circumvent this with a single line of code in a bot.

There are ways to make it harder to circumvent, though -- use all random field names, insert the hidden field at random locations in the sequence of fields, etc.. I'm still using the simple approach, though, since it's still working. :)