Captchas and anti-spam Gems

#	Total Rank	Daily Rank	Name	Summary
1	614	831	recaptcha	Helpers for the reCAPTCHA API
2	1,134	1,911	invisible_captcha	Unobtrusive, flexible and complete spam protection for Rails applications using honeypo...
3	2,311	2,131	voight_kampff	Voight-Kampff detects bots, spiders, crawlers and replicants
4	4,856	5,041	rakismet	Rakismet is the easiest way to integrate Akismet or TypePad's AntiSpam into your Rails ...