Automatically highlight word under cursor if it appears more than once in the file.

gistfile1.vim

" Clean-up of Swicher's Highlighter()
" Barry Arthur  2012-09-15

function! Highlighter()
  let word_cursor = escape(expand('<cword>'), ".*[]\\")
  redir => output
    silent! execute '%s/\<'.word_cursor.'\>//gen'
  redir END
  if output != ""
    if str2nr(split(output)[0]) > 1
      execute printf('match IncSearch /\<%s\>/', word_cursor)
    endif
    normal ``
  endif
endfunction

augroup Highlighter
  au!
  au CursorMoved * call Highlighter()
augroup END

set updatetime=300