Aaron's got the view>orient>N,S,E,W shortcuts which allows you to work in "plan" and "elevation" in a 3D view and Revit will let you move objects around as if you were in a plan or elevation view -- this can be a real time saver. Ours is OE,OW,OS,ON for orient east,west,south,north, OT for orient top (plan) OP for orient to plane.
F2 toggles the Project Browser
F3 is the Snaps dialog (sim to Acad)
F4 is Object Styles
F5 is Refresh (sim to Acad)
F6 toggles Thin Lines mode
F7 is spell check
F8 toggles Dynamic View (the X key does too when working on a laptop)
F9 is the Plane Selector dialog
F11 toggles the Status Bar
F12 toggles work plane visibility
It's interesting to see how people set their commands up -- some good ideas here and I wondered if people had developed some one-key commands.