Talking about LED's and Telephones and seeing you are all turning my thread into a comedy section I thought I would add to the mix ...

Reminded me of an incredibly funny segment from a comedy show I saw years ago...

It was highlighting an invention for deaf people so they would know when the phone rang. Basically they wore a device on the head which flashed an LED when their phone rang. Initially you thought what a great Idea until it actually flashed and the DEAF person wandered over and answered the phone. "HELLO, HELLO is anyone there ..... HELLO HELLO ..... HELLO ...."

On the same vain the interrupt for the blind sky diver, so that he knows when to pull the rip cord, is when the lead to the seeing eye dog goes slack.