SI CAPTCHA plugin:
Adds CAPTCHA anti-spam methods to WordPress forms for comments, registration, lost password, login, or all. In order to post comments or register, users will have to type in the code shown on the image. This prevents spam from automated bots. Adds security. Works great with Akismet. Also is fully WP, WPMU, and BuddyPress compatible.
2.7.6.4
- (05 Jan 2013) – added new setting “Enable honeypot spambot trap”. Enables empty field and time based token honyepot traps. For best results, do not enable unless you have a spam bot problem. Does not stop human spammers.
- fixed some bugs.