The site I do a lot of work for, Bink.nu, has three ways of getting to the content: http://bink.nu, http://www.bink.nu, and http://winxp.bink.nu.

http://bink.nu = PR7
http://www.bink.nu = PR6
http://winxp.bink.nu = PR6

Keep in mind, all of those URLs are the exact same website. Would it be beneficial to get rid of winxp.bink.nu? I'm just fearing that becase we have so many urls, links to our site is spread out over different base URLs, and Google thinks that http://winxp.bink.nu and http://bink.nu are different sites (and thus giving them different PR ratings).

Any comments?

It's horrendous practice to keep all three URLs active. First choose one URL you want to use from now on. Preferably it would be with the www, but bink.nu has a high PR without it, so I would go with that. Use an .htaccess file to 301 Redirect www.bink.nu and winxp.bink.nu to bink.nu. At the end of google's next update, it will take into consideration it's the same page, and PR will (I believe) be forwarded, along with all backlinks. Check out http://www.daniweb.com/forums/thread7965.html for more info.

The problem is that you are playing Russian Roulette with the duplicate content filters - best to use a 301 redirect on 2 of the domain names, or simply park them on the other domain.