Amazon has pulled the sales rankings of books with queer and feminist content, calling them "adult" books. (Apparently this has been going on for months. EDIT: Or possibly since last year.) Here's a list of the affected books, which includes such filthy smut as Heather Has Two Mommies, The Mayor of Castro Street, and Brokeback Mountain. The policy is being applied very inconsistently; in some cases one edition of a book has been de-ranked while another has not. If you do look up books by title, in some cases Amazon only permits you to purchase the Kindle version, which of course puts more money in their pockets.
I recommend complaining to Amazon, supporting other bookstores (such as Powell's, which is considering a GLBT book sale in response), signing this petition, commenting in support of this open letter, and possibly participating in a Googlebomb of "Amazon Rank", though I'm holding off on that last until I hear more authors say it's a good idea and won't hurt people searching for their books.
If you see any other relevant links, send 'em my way.
EDIT: If you want to see what de-ranking means in the real world, go to amazon.com and search for "homosexuality". You get a) a list of recommended searches topped by "homosexuality and the Bible", "homosexuality and the politics of truth" (I'm not even sure what that means), "homosexuality and Christianity", and "homosexuality and the Catholic Church", and b) a list of books starting with A Parent's Guide to Preventing Homosexuality, You Don't Have to Be Gay, and Can Homosexuality Be Healed?. I am speechless.