When I got home last night, her room was (relatively) clean. She's still restricted from phone, TV, & computer. And the new deal (thanks to Beck's suggestion) is this:
If, at any time, I go into her room and find clothes on the floor, I will confiscate them. She'll be able to buy them back - we'll start at $0.50 for socks/underwear and $1.00 for other items of clothing. And, as several of you suggested, she's totally responsible for her laundry. I've read her the riot act, and read Rob the riot act (he's notorious for giving in on stuff like that).
We had a discussion on the way home from the basketball game about the fact that she's not only being a slob, but that she's showing absolutely no respect for the fact that we work hard to buy her these clothes. And that if the situation does not improve, her wardrobe funds will be cut off. With Hollister opening next week, them's fighting words.
Thank you, everyone, for your suggestions (and yes, I mean you, Mom).