Vim 80 column layout concerns

Shorter way:

match ErrorMsg '\%>80v.\+'

I have this set up in my .vimrc:

highlight OverLength ctermbg=red ctermfg=white guibg=#592929
match OverLength /\%81v.\+/

This highlights the background in a subtle red for text that goes over the 80 column limit (subtle in GUI mode, anyway - in terminal mode it's less so).

I prefer:

highlight ColorColumn ctermbg=gray
set colorcolumn=80

As of vim 7.3, you can use set colorcolumn=80 (set cc=80 for short).

Since earlier versions do not support this, my .vimrc uses instead:

if exists('+colorcolumn')
  set colorcolumn=80
else
  au BufWinEnter * let w:m2=matchadd('ErrorMsg', '\%>80v.\+', -1)
endif

See also the online documentation on the colorcolumn option.