Emacs Shortcuts

Basics
M-y Replace previous paste with the previous clipboard content
C-u N Repeat the following command N times
C-x C-m f Change file encoding
Abbrevs
C-x a g Add a global abbrev
C-x a l Add a local (mode) abbrev
C-u - C-x a [gl] Remove a global/local abbrev
C-q Don’t expand this word.
Outline mode
(Remove C-o if not in TeX-mode)
C-c C-o C-t Hide all
C-c C-o C-a Show all
C-c C-o C-e Show this one
C-c C-o C-c Hide this one
Rectangles
C-x r k Kill a rectangle
C-x r y Yank a rectangle
C-x r t Replaces the contents of a region-rectangle with a string on each line
Keyboard macros
C-x ( Start a new macro
C-x ) Finish the new macro
C-x e Execute the most recently defined macro
C-x C-k Edit the most recently defined macro
C-u C-x ( Execute and add keys to the most recently defined macro
name-last-kbd-macro Give a name to the most recently defined macro
apply-macro-to-region-lines Run the last keyboard macro on each complete line in the region.
Auctex
C-c e Insert a new item
C-c C-c Make an action (compile, view)
C-c   Goto next error
C-c ) Insert a reference (reftex)
Gnus
S o p Forward a news to a newsgroup
Etags / Ebrowse
Creating the BROWSE file: ebrowse **/*.{cpp,h,hpp}
Creating the TAGS file: etags **/*.{cpp,h,hpp}
C-c b s Look for a tag in all files
C-c b u Look for the calls to the selected member
c b , Continue the last operation
C-c b % Query replace a tag in all files