This weekend my wife and I hiked to the top of Squaw Peak, also called Piestewa Peak. It was recently renamed after a Hopi soldier, Lorie Piestewa, who was killed in Iraq, although most people still call it by its old, and less PC name, Squaw Peak.
Its a sharp peak within a wilderness reserve right in the middle of Phoenix. Its one of the few places you can go in the city and actually feel like you are in nature. It was a pretty difficult hike, I thought anyway, and took us from about 1400 feet above sea level to about 26oo ft asl in a little over a mile (e.g. straight up with many switchbacks).
It was a pretty hard hike but we were rewarded with great views of the city and surrounding mountain ranges at the top. We even got to see a rather rare lizard for this area, a Common Chuckwalla. Below are some pics from the hike.