Snowboarding is a tad out of reach with the drive to Tahoe, but not undoable. (Yeah, it looks quick on the map, but OH GOD THE TRAFFIC)
www.bayareaskibus.com helps with the traffic. You pay a little extra and then don't have to worry about driving. You can use the 8 hour round-trip to sleep, read your Kindle, watch movies, etc.
(I'm not affiliated w/them in any way, but I've used them ~15 times and am a happy customer.)
But if you're talking about hiking hills and lower peaks (to ~5,000'), surfing, windsurfing, etc., then from any of the major population areas (San Jose, Penninsula, San Francisco, East Bay), odds are good you're within 45 minutes of good waves, 20 minutes to water period, and in many places, can simply walk to a trailhead.
Sacramento is a good 80 miles from San Francisco, and isn't considered "Silicon Valley" by any means. Even there, you can find recreational cycling pretty much anywhere outside city limits, or the American River Trail. The Sierra's that much closer, with a 1 hour drive up I-80 or US 50 taking you to prime hiking spots.