Then find some expensive phones that are 16 or 32 Ohms? I'm using some cheap phones from woot with my N800; going from memory, I think they're ARE05s: 32 Ohm impedance and 16mm drivers. Even at full volume, I can barely hear any noise when the output is active, but playing silence.

As for the click, I do hear a slight click (not really annoying, but definitely noticeable, at full volume) when the output is enabled or disabled, but not between tracks. (The output only seems to be disabled after about 2 seconds, so even if your media player opens and closes it between each track, it wouldn't trigger this click.) I think what you're hearing may be either lack of complete gapless playback, if your tracks are back-to-back (there's a number of partial implementations, as well as completely naive non-gapless approaches.), or just a plain bug (if it happens even on tracks with complete silence at both ends).