I remember in the mid 90s just as mobile phones were really taking off here, if I was on a bus listening to my walkman, I'd always know when someone's phone was going to go off because there would be this weird "chakara~chakara~chakara" sound in my headphones or earbuds.
A couple of months back, I was recording a friend singing and she kept stopping to text. It was getting kind of wearing ! We were doing a song ostensibly about a space invasion and as she began the third verse, her mobile made this noise to tell her she had a text. But it was a happy accident and I kept it on her vocal track. Sounded oddly appropriate........
Kind of off topic, but the most common noise when I record are my drumming friends moving on the seat when a track has finished and you need like 20 seconds silence. I always motion to them to keep still but they just can't seem to !