Distraction Free Writing with Vim

I recently configured Vim to switch to a special writing mode upon opening Markdown files. It helps me to keep the focus while writing avoiding distractions. I first saw this concept in iA Writer and immediately fell in love with it. However, my muscle memory was too tied with Vim and I didn't want to switch to a different editing environment solely for this purpose. Hence, I tried to make Vim to behave in a similar manner.

Check this screencast to see it in action:

For anyone interested, these are the steps I took to setup it. Please note that I tried this with MacVim on OS X Lion. It may not work as expected in other versions or other OSs.

Installed syntax highlighting plugin for Markdown.
Enabled iA Writer color scheme for Vim. I made some customizations to get the current appearance.
Added the following custom function into .vimrc, to run when a Markdown file is created or opened.

    " turn-on distraction free writing mode for markdown files
    au BufNewFile,BufRead *.{md,mdown,mkd,mkdn,markdown,mdwn} call DistractionFreeWriting()

    function! DistractionFreeWriting()
        colorscheme iawriter
        set background=light
        set gfn=Cousine:h14                " font to use
        set lines=40 columns=100           " size of the editable area
        set fuoptions=background:#00f5f6f6 " macvim specific setting for editor's background color
        set guioptions-=r                  " remove right scrollbar
        set laststatus=0                   " don't show status line
        set noruler                        " don't show ruler
        set fullscreen                     " go to fullscreen editing mode
        set linebreak                      " break the lines on words
    endfunction

I also added this setting to .vimrc, to toggle SpellChecking in normal mode.

    :map <F5> :setlocal spell! spelllang=en_us<CR>

Installed the Cousine font. It's a free alternative to Nitti Light, the font used by iA Writer.
Turned off Mac OS X's native full-screen mode for MacVim (otherwise the custom background color is not applied).

    defaults write org.vim.MacVim MMNativeFullScreen 0

You can find the customized versions of all needed files in this Git repo.

Update: I extracted the distraction free mode settings into its own plugin and allowed it to be toggled from the F4 key (now it won't be forced upon opening Markdown files). Check the repo in GitHub for updated settings.