Don't forget your passport and your identification card such as driver license. They might ask you if you have travelled recently out of USA after N-400 interview and they might look at your passport if there is any recent/last US entry stamp. In fact, my relative was asked for passport, driver license, gc, and oath letter when entered the ceremony site. The Officer asked "have you travelled recently after the N-400 interview?"
I agree with atlanta_brother. just bring paperwork and leave it in your car trunk (just secured properly) or have your friend or relative carry it for you.