For the good of humanity I implore you, I beseech you, I ardently request of you and I will even downright beg of you… UPGRADE YOUR BROWSER!
Even if you stay with Microsoft and upgrade to a newer version of IE, you need to get a newer browser. Not only is it safer in terms of security, its also easier for me to do my job and produce websites which work better without having to add hacks to make IE 6 render properly.
A lot of them are probably bots and obscure browsers intentionally mis-identifying themselves as IE6.
/knowitall
Firstly, you should be ignoring that and siding with me on this.
Secondly, shut up you git
Who are they?!?
You can’t blame me for that. I may have used dial-up for 10 years, but I don’t use IE6
But you will still get people using it, though. You may even find some still on IE5! 
Have you tried Statcounter (it’s very WordPress friendly) gives very nice stats about each user and has a great map showing all the worldwide locations of each visitor. I haven’t seen Google Analytics in years, it was crap when I tried it, but probably is a lot better now.
Bloody hell. Stop leaving logical, sensible answers you people.
Matt: Dunno. Goggle analytics is too vague on specific people.
Hermit: I can blame you for anything i like.
Closov: Analytics is pretty good for head counting and it does show a worldwide map… come to think of it, i’ve given the other two access to my analytics already. I should give you access as well.