CNET Radio (AM 910) has been my constant companion for the last year or more. It’s delivered technology news and talk all day, every day – and now it’s closing up the radio station on January 31. Sad news for anyone who had stumbled on its wonderful programming in the San Francisco area, or nationwide on XM Radio. (Rob Black’s commentary on investing and the stock market is addictive.) Driving around goes back to being dull. Sniff.