It's been 30 years since I've gone rock climbing on a regular basis, and I wasn't sure how to get back into it, so I decided to take a one-hour belay lesson at Planet Granite in Sunnyvale. I went on a Monday night, and the place was packed -- mostly with twenty- and thirty-somethings, but also a good mix of teenagers and middle-agers just off work. Half the facility is dedicated to climbing, with tall "rock faces" studded with handholds and footholds; the other half has exercise equipment, free weights, a yoga studio and locker rooms. Even though I was rusty, the belay instructor and the three other students (all much more experienced than I was) were very patient, and by the end of the class I was able to belay up and down a climbing wall like it was 1983. A day pass costs $20 ($26 if you want to rent climbing shoes and a harness), and membership fees are $75 a month (with access to Planet Granite locations in Sunnyvale, Fremont and San Francisco; unlimited climbing; use of fitness equipment and weights; and unlimited yoga).