Ok, so we all know speed is of the essence, right? We all get bored when working out the software takes over from a mad jam session. Ask any true Geek or I.T. professional and they'll tell you - "Know your keyboard shortcuts." This applies with 99.99% of programs, so why not spend a few minutes and make your life that much easier.
So... here are the most useful shortcuts for LIVE (based on Version 6). Consult the PDF manual for complete descriptions.
If anyone is still unsure what these mean feel free to ask.

CTRL+1: Reduce time grid resolution.
CTRL+2: Enlarge time grid resolution.
CTRL+3: Toggles triplet mode on and off.
CTRL+4: Disable grid, no snapping.
CTRL+5: Disable grid zoom lock, no snapping.
CTRL+B: Switchs between pencil and pointer editing tools.
CTRL+D: Duplicate selected blocks.
CTRL+E: Splits midi/audio blocks.
CTRL+F: Follow play timeline.
CTRL+I: Insert silence.
CTRL+J: Consolidate midi/audio blocks.
CTRL+K: Edit key map.
CTRL+L: Sets markers and loop around selected time.
CTRL+M: Edit midi map.
CTRL+R: Rename track.
CTRL+DEL: Delete only selected automation channel dots.
CTRL+X,C,V,O,S,N,A: Cut, copy, paste, open, save, new, select all options.
CTRL+ALT+C,V,X,D: Copy, paste, cut & duplicate envelope automation.
CTRL+T: Insert new audio track.
CTRL+SHIFT+T: Insert new midi track.
CTRL+ALT+T: Insert new return track.
CTRL+SHIFT+D: Duplicate selected time.
CTRL+SHIFT+M: Create midi block in the selected area.
CTRL+SHIFT+R: Render loop.
CTRL+SHIFT+DEL: Delete selected time.
F1/F8: mutes and unmutes mixer channels 1 to 8.
F9: Record ON
F11: Switch to fullscreen mode.
F12: Switch between vst and fx and midi block panel.