The Narrows is a nice "hike" if you are in Zion during a hot day (any time in summer). The trail starts art the end of Zion Canyon Scenic Dr, also called the "Riverside Trail". Go as far as you like up the river but step carefully, as the water can get chest high in some places.
This was awesome! I went to Zion as part of a week-long south west road trip after graduation. It was about 95 degrees on the day we got here, so hiking to Angels landing did not seem like much fun. Instead we walked through the cool water for 2 hours and had a blast. Visited on Jun 28, 2009