vim config file with minimal changes compared to default debian squeeze:

aptitude install vim
update-alternatives --set editor /usr/bin/vim.basic

~/.vimrc

" All system-wide defaults are set in $VIMRUNTIME/debian.vim (usually just
" /usr/share/vim/vimcurrent/debian.vim) and sourced by the call to :runtime
" you can find below.  If you wish to change any of those settings, you should
" do it in this file (/etc/vim/vimrc), since debian.vim will be overwritten
" everytime an upgrade of the vim packages is performed.  It is recommended to
" make changes after sourcing debian.vim since it alters the value of the
" 'compatible' option.

" This line should not be removed as it ensures that various options are
" properly set to work with the Vim-related packages available in Debian.
runtime! debian.vim

" Uncomment the next line to make Vim more Vi-compatible
" NOTE: debian.vim sets 'nocompatible'.  Setting 'compatible' changes numerous
" options, so any other options should be set AFTER setting 'compatible'.
"set compatible

" Vim5 and later versions support syntax highlighting. Uncommenting the next
" line enables syntax highlighting by default.
syntax on

" If using a dark background within the editing area and syntax highlighting
" turn on this option as well
"set background=dark

" Uncomment the following to have Vim jump to the last position when
" reopening a file
"if has("autocmd")
"  au BufReadPost * if line("'\"") > 1 && line("'\"") <= line("$") | exe "normal! g'\"" | endif
"endif

" Uncomment the following to have Vim load indentation rules and plugins
" according to the detected filetype.
"if has("autocmd")
"  filetype plugin indent on
"endif

" The following are commented out as they cause vim to behave a lot
" differently from regular Vi. They are highly recommended though.
"set showcmd            " Show (partial) command in status line.
set showmatch           " Show matching brackets.
"set ignorecase         " Do case insensitive matching
"set smartcase          " Do smart case matching
"set incsearch          " Incremental search
"set autowrite          " Automatically save before commands like :next and :make
"set hidden             " Hide buffers when they are abandoned
"set mouse=a            " Enable mouse usage (all modes)
set number              " display line numbers

set autoindent          " copy the indentation from the previous line, when starting a new line
set tabstop=4           " Insert 4 spaces for a tab
set expandtab           " To insert space characters whenever the tab key is pressed
set shiftwidth=4        " To change the number of space characters inserted for indentation

set pastetoggle=<F2>    " disable/enable autoindent to paste without messing up formatting

" Source a global configuration file if available
if filereadable("/etc/vim/vimrc.local")
  source /etc/vim/vimrc.local
endif

map <C-n> :tabnext<CR> 

To integrade available addons into vim the addon-manager is needed:

# 1st the manager is needed:
aptitude install vim-addon-manager
 
#2nd an addon can be installed:
aptitude install vim-puppet
 
#3rd activate the addon 
#   (only for current user)
vim-addons install puppet
#   (for all users system wide)
vim-addons -w install puppet
 
# list what is configured:
vim-addons
 
# Name                     User Status  System Status
editexisting                removed       removed
justify                     removed       removed
matchit                     removed       removed
puppet                      installed     removed

Undo a change:

u

Redo an undo:

ctrl-R

To change all the existing tab characters to match the current tab settings, use:

:retab

To convert only the current line to to match the current tab settings, use:

:.retab

To insert space characters when you press the tab key, set the 'expandtab' option. If you need a real tab charater with this option set, use Ctrl-V<Tab> key sequence

:set expandtab

To comment out a block of code (#): enter visual mode (V), then search & replace:

" comment out:
:s/^/# /

" remove comment:
:s/^# //

Remove 4 spaces in front of (#) as below:

    # Some comment(s)
    # lorem ipsum

:s/^\s\{4}//g

the result will be:

# Some comment(s)
# lorem ipsum

do the opposite, insert 4 spaces:

:s/^/    /g

Use tabs within vim.

Open two files at once in tabs:

vim -p file1 file2 

Open a file into a new tab:

:tabf filename

Switch between tabs:

:tabn
:tabp
:tabfirst
:tablast

Make switching tabs even easier:

# add the following line to your ~/.vimrc and you can press <ctrl><n> to switch between tabs!
map <C-n> :tabnext<CR>

List tabs:

:tabs

Run a command in all open tabs (replace alle occurrences of “old” with “new”):

:tabdo %s/old/new/g

The big tab manual:

:help tab-page-intro

• http://www.catonmat.net/blog/vim-plugins-snipmate-vim/
• http://www.catonmat.net/blog/vim-plugins-ragtag-allml-vim/