A few days ago, Adam Brown, the head of digital communications at Coca-Cola, got his car washed and the sun shone down on him in Atlanta. Meanwhile, Bart Cas, his opposite number at Pepsi, went for a run on the Brooklyn Bridge.

I happen to know these details because last week I stumbled upon Exec Tweets, a collection of about 100 executives who like to express themselves in chunks of up to 140 characters on Twitter.