[waps]

> Eventually, the spammers will make a bot to analyze the distance between dots, group them into letters, and the race will be on to use other methods. I see this as a never ending virus/immunity battle. We're pretty much at the end of Captchas. Other methods like mouse movement, surfing time, scrolling, etc... can all be mimiced as well. Computers can or will be able to simulate humans very well, even our imperfections.

Love your optimism. I'd like to say that captchas are very limited : they have to be solvable by idiot humans. Captcha algorithms have no such limits they have to abide by. Since the anti-spam side of things is blocked at a certain point in the arms race, the other side is bound to win.

Why not just require, say, a google or facebook login and transfer the "eliminate spammers" problem onto them ?