It might sound obvious, but...
The quickest way to flip the screen on any device, is to only redraw the bits you need to.
Eg: Are you re-drawing things like status bars etc, even when they are not changed?
If you think your flip is bad, try a HP Jornada 680. It has a flip time of ~100ms (640x240). It will struggle to clear the screen at 10 fps with nothing else going on!!!
[edit]
(1/(17/1000)) = ~58.8. Not a VSync is it?
