cheat sheets.

Emacs for Ruby & Rails

From ruby-mode.el
M-C-a            Beginning of defun
M-C-e            End of defun
M-C-b or M-C-p   Beginning of block
M-C-f or M-C-n   End of block
M-C-h            Mark defun
\t               Indent
C-c C-e          Insert end
C-j              Reindent then newline and indent
C-m              Newline

From inf-ruby.el
C-c C-e or M-C-x "send the current definition to the process buffer"
C-c M-e          "switch to ruby process buffer after sending their text"
C-c C-r          "send the current region to the process buffer"
C-c M-r          "switch to ruby process buffer after sending their text"
C-c C-z          "switches the current buffer to the ruby process buffer"
C-c C-l          "Load a Ruby file into the inferior Ruby process."
C-c C-s or M-x run-ruby  "Run an inferior Ruby process..."

Unicode in Emacs:
(prefer-coding-system 'utf-8)

Emacs opens in yaml-mode and outdent-mode when first line is:
# -*- mode: yaml; mode: outdent; -*-

For more:
http://wiki.rubyonrails.org/rails/pages/HowToUseEmacsWithRails