Hassan Schroeder wrote: > On Sat, Aug 8, 2009 at 6:38 PM, Jeremy Weiss<eccentric.one at gmail.com> > wrote: > > I've seen CAPTCHAs that sucked, yes, but personally I'd be more > inclined to just go with the "what's 2 + 2" question approach rather > than stretch too far into interpretation based on what may not be a > shared worldview. > > I know I shouldn't but can't resist. I regularly misread captcha - > really detest them. However, simple math if fairly universally > understood and works. > Side note - I'd swear that with Craigslist I've posted ads and if I get 80% of the characters right, they go through. > If you want to take it to level 2, it'd be pretty easy to use > imagemagick/convert to display two very readable (not pop art) images > as numbers. > % convert -background white -fill black -border 5 -bordercolor white -pointsize 30 label:'2 + 7 = ?' math.gif Program in: $result = $var1 + $var2 % convert -background white -fill black -border 5 -bordercolor white -pointsize 30 label:'%var1 + $var2 = ?' math.gif That being said in general I prefer if possible using techniques that prevent spammers/spambots from filling in forms by addressing their repetitive behavior patterns. Also someone (can't find the email) made a super suggestion regarding placing a "administrator use only" field on the form and if filled in, deny the submission.