I heard "The Da Vinci Code" is a good read. maybe you've heard of it?
I recommend "Naked" by David Sedaris. I've read it three times and I still pee my pants a little I laugh so hard at it.
I guess these books won't make you shine on an EM rotation though.
Looking back on my 4th year EM rotation, the things that would have really impressed my attendings ( and the qualities that impress me about medical students now) are developing a broad differential diagnosis, knowing how to read basic EKG rhythms, and knowing ACLS. Pick up an ACLS book and read it. I also recommend Garcia's "Art of EKG interpretation". Know the basics of treating a cardiac emergency. If you don't know when to shock someone, you won't make a good impression.
Know how to do a pelvic. I really impressed several attendings by being able to confidently go in and do a thorough pelvic exam. It is a 100% certainty that you will be doing at least 1-2 pelvics during your EM month and it is also a 100% certainty that you will be supervised by an attending while you do it. Here's your chance to shine and show you've got confidence, knowledge, people skills, sensitivity, and maturity.
Good luck!!!! EM rocks.