My fuel pump changes pitch when the [turn signals/radio/lights/other electrical device] is on! Is there a fix?

This is normal, and is a symptom of the alternator voltage dropping while under load - the same reason why headlights tend to dim at idle. Tom Stangl did some testing with a fuel pressure gauge and found that his fuel pressure remained 'rock solid' despite the changing noise of the fuel pump, indicating the pump is still pushing more fuel than the fuel pressure regulator needs.

Those who find this problem annoying or worrisome can fix it (or at least mitigate it somewhat) by doing the fuel pump wiring upgrade described here.