Today, I found the answer: Craigslist Helper. (Alright, I agree, the name is about as boring as the typical Craigslist site but it gets better.)
Users can efficiently preview and zoom through their browser, greatly increasing the efficiency for addicted deal-seekers like myself.
Still needing your social networking fix to be impressed? Check out Keepio, a selling site that emphasizes a community to "sell, share, or swap" with a network of your own friends.
And, hey, there's always a garage sale!