I have been working more on the bot filter for my website, but by no means is it complete.
So far I have the main ones:
Google, Yahoo, MSN, Baidu, Amazon, and a few others...
Right now, I am using a filter to compare the referral URL, existing domain, and known browsers vs. non-browser useragents.
Are there any other good techniques to detect if the hit is coming from a bot or not?