website visitor tracking

[yoda]

I'm after an 'addon' to my new site so that I can track them wherever they go on my site and I can pull off info such as OS, browser prog, screen resolution, CPU, RAM... ect

Anyone know of any good free ones?

The alternate is to make my own... so does anyone knoe how to access that info in PHP?

Thanks

:edit
Also, I want to know how they got to my site and if it was by a search engine then what keywords did they use...

So whats the best?

 

[yoda]

ok, installed BBCLONE....
i want more stats.... I like figures... I'm worse than big bro...

what are the others?