Extremely basic, no-configuration registration spam bot trap
A simple, no-configuration plugin that adds spambot trap fields to the WordPress registration form.
Tested only with WordPress 2.6 and 2.7 but should work with earlier (and later) versions.
More information available at: http://room34.com/downloads/wppi/registrap
RegisTrap is made available free of charge. You are free to use, alter and distribute it, provided any distribution retains this file and any modified versions are clearly identified as such.
THIS SOFTWARE IS PROVIDED AS-IS WITH ABSOLUTELY NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK.