Amusing Planet posted a blog with GREAT pictures about Half Dome and the joys of hiking to the top.
From the article:
The trail starts with a 13.7 km hike, followed by a rigorous 3.2 km approach including several hundred feet of granite stairs. The final 400-foot ascent up the peak’s steep but somewhat rounded east face is ascended with the aid of a pair of post-mounted braided steel cables raised on posts that lead to the breath-taking summit. This cable route was constructed close to the Anderson route in 1919 by the Sierra Club for visitors who have no rock climbing ability or equipment. Following the Half Dome Cables Trail is a unique experience, and it has become one of the most popular hikes in Yosemite National Park. As many as 1,000 hikers per day have sometimes climbed the dome on a summer weekend, and about 50,000 hikers climb it every year.