Vehicle construction:
In the VAB, when holding ALT while placing a part - snap mode is off.
Select your assembly by its anchor, copy it with CTRL+C then paste it in a text editor or send it to a friend who can then paste it with CTRL + V in his workspace
After selecting the translation / rotation tool, press F to change it's frame of reference
Flight:
Hold ALT + WASDQE to adjust the trim of your aircraft (changes the neutral flight position of control surfaces)
ALT+X resets trim
You can press CapsLock to enable fine control (especially useful when using physics time warp)
General:
You can click and drag to scroll through lists.