API call to get total API calls remaining

API call to get total API calls remaining

It would be very helpful if I could do an API call that would tell me how many API calls I have remaining that would be great.

It would make it even greater if that DIDN'T count as an API call itself.

I have many scripts that do API calls but there are all separate (Some even reside on separate servers).  Knowing how many API calls I have remaining would allow me to exit my script nicely if no API calls remain.