bot detection

[CS-Jay]

I am in the middle of writing a link trade script. I was wondering what's the best way to detect that a incoming hit is a human or bot? I am writing this in php.

Check see if they can pull an image? javascript? or cookie?

[PPC]

hm.. check to see if they're using an open proxy... I know this doesnt cover all bases.

lol captchas

[vas]

proxy detection
productivity tracking
1 pixel image with link to detect the sneakier bots...

just to name a few

[CurrentlySober]

poo. see if they poo...

poo = human...
no poo = bot...

i like poo

[sniperwolf]

poo. see if they poo...

poo = human...
no poo = bot...

i like poo

[GrouchyAdmin]

<input type="checkbox" name="amiabot" checked>Are you a bot?

[Mike Semen]

poo. see if they poo...

poo = human...
no poo = bot...

i like poo