In search of the perfect CAPTCHA

An example of a not-so-good CAPTCHA. Source

Great article in Smashing Magazine at http://www.smashingmagazine.com/2011/03/04/in-search-of-the-perfect-captcha/

It mentions "So many websites offer social-networking integration that services like Janrain have popped up. Janrain provides an abstracted umbrella solution to ensure that websites are accessible through any account platform" 

Conclusion:

Understanding the alternatives (whereby spam detection is silent to users) and implementing them on our clients’ websites is a good start. It’s a positive step toward usability and conversion rates (and clients will love that!). If users comment on your website, reward them with a simple experience. This can be done in several ways:

• Moderation wherever possible
  Disallow certain content to be posted directly to your website, or allow it through maintained and verified account management. Better yet, use a service like Facebook Connect or Disqus; you’ll make things easier for both yourself and users.
• CAPTCHA alternatives
  Try the honeypot method or another that is invisible to users. Some could potentially be bypassed, but their presence is often enough to thwart automated efforts.
• Client-side detection
  This can work because, while there are simple workarounds, spammers won’t waste time (for now). Keyword and mouse interactions can be used to detect genuine user input. This option shouldn’t be used on its own but can add extra assurance.
• Server-side spam detection
  Developers should focus on server-side spam detection that monitors users and flags unusual activity. Specialist services like Akismet are affordable and proven, but bespoke systems can be tailored to the nuances of your website.
• Social moderation
  Move toward more sophisticated features that allow this. The simple act of voting content up and down can help to push spam away or flag it for deletion.

It seems clear, considering all the pros and cons of CAPTCHA, that the future lies in a system that is invisible to normal Web use. For now, using a CAPTCHA should be your last resort.