I'd like to know how anyone can get a book published without an agent. I've been doing this (trying to, that is) for more than 30 years and I don't know of ANY publisher who will read an unsolicited manuscript. The field, as I see it, is set up like this: a publisher doesn't want you unless you're represented by an agent, who doesn't want you unless you have literally knocked their socks off with the query letter to end all query letters, and if the query letter doesn't turn their crank, you're stuck out in the cold. You may have the next Catcher in the Rye resting comfortably in your filing cabinet for the rest of your life, but unless you nail the publishing world with that perfect query letter, you're just another rank amateur no one cares about.
Did I get it right?
Well, yes, except for most of what you said, which was technically incorrect. First of all, my boss often does not wear socks with her sandals like I do. Second, I'm not sure what a crank has to do with being cold, but if we're supposed to have one of those crank things in the office, I should put in a complaint with the guys we rent from. I will say that it is very cold in our offices and I'm often wearing my coat in the summer, but they can't do anything about it because it's central air.
Now that I'm done being a smartass, I will say that any amount of research will inform you that may publishers DO take unsolicited manuscripts, and some of them even accept and publish them! Who knew! Publishers include Tor, Sourcebooks, Baen Books, Ace Books, Daw Books, several divisions of Harlequin Enterprises, and basically every small/independent press known to man.
Though specifically sci-fi/fantasy oriented, a great place to look up publishers and magazines that take unsolicited material is Ralan.com.