Not a diversion as such, but back in 2001 I was a regular on GLA - EMA with BMi. It was often a small Fokker and never that busy. On boarding one afternoon in GLA, the Captain announced that a similar flight EDI - EMA had been cancelled, so we would be popping over to pick the pax up before carrying on down to EMA. So we did, took about ten minutes in all, flying down the route of the M8 corridor, and then carried on our way. It was the demise of BMi that led to me being in BAEC, I had been a confirmed *A flyer up till then.