Singer/songwriter/guitar-hero John Mayer, known in the Valley for his onstage appearances with Steve Jobs to demo Apple's GarageBand software, isn't living up (or down) to his onstage claims that he spends a lot of time alone in his bedroom — you know, with his guitar. Gossip rags report that Jobs's musician buddy was seen shnozzing with both Shrek voice actress Cameron Diaz and Friday Night Lights star Minka Kelly on separate dates over the weekend. We can only surmise that Jobs's reality distortion field works on actresses, too.