Last week I got paid to hike North Rim to South Rim for my new job. It was an awesome hike with 7 park service interpretive staff that knew practically anything there was to know about the Canyon.
We took four days to cross the Canyon, which is much slower than most people get the opportunity for, but we were stopping at almost every rock laer change, new plant, insect, etc to share knowledge. Stayed at Cottonwood campground on the way down, Phantom Ranch, and Indian Garden on the way back up, with a side trip out to Plateau Point.
Pics are at http://picasaweb.google.com/jnetxpic/GrandCanyonRimToRim#