Doug,

I started using Compassion Flight etc and changing my 'N-number'. I was
getting questioned so much by ATC, that I figured it wasn't worth it. So,
now I just use my N-number, but if I need 'special attention' I add, "...and
we're an Angel Flight today". Occasionally I also add "...and we have a
really cute girl in the back who can't wait to get home" (or something
similar). FWIW: That works like a charm, from jumping to #1 from #7 at PAO,
to flying the PAO approach with no delay (in IMC) etc. But while getting
handed off on a long XC, I just use my N-number.

Hilton