I read the first 12 pages of The Adoration of Jenna Fox to my freshman classes today. They were very interested and got pretty upset at me when I stopped reading. Yay!
It's a really good choice for a read aloud because it has a LOT of mystery at the beginning, and the whole thing slowly unravels. Plus it doesn't really have chapters, it has short sections with poems mixed in, so there are lots of good stopping places.
Hopefully it goes well with the sophomores tomorrow, too.