Timeline (DHTML)

Select next/previous keyframe	or
Select next/previous track	or
Play a scene beginning at the current time cursor location	Enter (numerical keypad)
Stop scene playback	0 (numerical keypad)
Create a new keyframe	Ctrl-click a time track
Duplicate a keyframe	Alt-drag keyframe
Create an action placeholder	Ctrl-click action on action track
Scale an animation while maintaining the relative time positions of all keyframes on the same time track	Ctrl + -drag

Shift Key