The following links are queer bookstores.  Let's keep our $3 bills circulating within the community.  All of these bookstores have online ordering available.

A Different Light Bookstore: Gay and Lesbian Literature.  I've been here and they've got a lot, ranging from works of so-called high theory to erotica.  They offer online ordering, and have been miracle-workers in hunting out out-of-print and hard-to-find books for me.  They sell any book that has something to do with lesbian, bisexual, transgender, gay, and queer topics.  I highly recommend them.

Afterwords Bookstore and Expresso Bar.  The selection here on their webpage was quite limited, unfortunately, but they do offer ordering online.  I doubt you'll find any queer theory here, however.

Ex Libris.  This is a Toronto-based bookstore that offers online ordering and specializes in both new and used gay/lesbian literature.  You can either browse their online store, or use their link to the Advanced Book Exchange to search for books.

Sapphisticate.  This bookstore also has a limited selection on the site itself, but offers both online ordering and a link to Amazon.com.  As the name may indicate, this is primarily a lesbian bookstore.  As with Afterwords, I doubt you'll find any queer theory here.