Listening to the radio these days I'm increasingly aware I'm hearing conversations between people who aren't in the same physical space.
They used to proudly announce these exchanges as being "down the line from" as if that proved how far their mighty arm extended. These days not so much, maybe because an increasing number of people aren't prepared to disrupt their entire day just to help fill a two-minute gap in a programme.
I could be wrong but I think BBC 5Live are particularly reluctant to flag up up how many interviewees are in London, which is of course where they used to be.
The remote interview is popular with company chairmen spinning their annual results on the Today Programme. They get an ISDN line installed in the office and then they can field the questions while surrounded by PR men holding up flash cards with key points on them.
Radio engineers hate Skype because of the quality. Interviewers don't like it because on a remote call it's difficult for them to butt in. Listening to Skype interviews you realise how much of the exchanges in an intervieware signalled physically.
One former Cabinet minister would always plead a packed calendar as his excuse for not being able to come to the Today studios. He knew that if they sent the radio car round he was in command. He was on his own turf rather than theirs, they couldn't intimidate him with so much as a raised eyebrow and once he was embarked on an answer he could talk as long as he liked.