Update 2012: I'd now really recommend checking out vim-powerline which has replaced my old statusline script, albeit currently missing a few features I miss.

I'd say that the statusline stuff in my vimrc was probably most interesting/useful out of the lot (ripped from the authors vimrc here and corresponding blog post here).

Screenshot:

status line http://img34.imageshack.us/img34/849/statusline.png

Code:

"recalculate the trailing whitespace warning when idle, and after saving autocmd cursorhold,bufwritepost * unlet! b:statusline_trailing_space_warning "return '[\s]' if trailing white space is detected "return '' otherwise function! StatuslineTrailingSpaceWarning() if !exists("b:statusline_trailing_space_warning") if !&modifiable let b:statusline_trailing_space_warning = '' return b:statusline_trailing_space_warning endif if search('\s\+$', 'nw') != 0 let b:statusline_trailing_space_warning = '[\s]' else let b:statusline_trailing_space_warning = '' endif endif return b:statusline_trailing_space_warning endfunction "return the syntax highlight group under the cursor '' function! StatuslineCurrentHighlight() let name = synIDattr(synID(line('.'),col('.'),1),'name') if name == '' return '' else return '[' . name . ']' endif endfunction "recalculate the tab warning flag when idle and after writing autocmd cursorhold,bufwritepost * unlet! b:statusline_tab_warning "return '[&et]' if &et is set wrong "return '[mixed-indenting]' if spaces and tabs are used to indent "return an empty string if everything is fine function! StatuslineTabWarning() if !exists("b:statusline_tab_warning") let b:statusline_tab_warning = '' if !&modifiable return b:statusline_tab_warning endif let tabs = search('^\t', 'nw') != 0 "find spaces that arent used as alignment in the first indent column let spaces = search('^ \{' . &ts . ',}[^\t]', 'nw') != 0 if tabs && spaces let b:statusline_tab_warning = '[mixed-indenting]' elseif (spaces && !&et) || (tabs && &et) let b:statusline_tab_warning = '[&et]' endif endif return b:statusline_tab_warning endfunction "recalculate the long line warning when idle and after saving autocmd cursorhold,bufwritepost * unlet! b:statusline_long_line_warning "return a warning for "long lines" where "long" is either &textwidth or 80 (if "no &textwidth is set) " "return '' if no long lines "return '[#x,my,$z] if long lines are found, were x is the number of long "lines, y is the median length of the long lines and z is the length of the "longest line function! StatuslineLongLineWarning() if !exists("b:statusline_long_line_warning") if !&modifiable let b:statusline_long_line_warning = '' return b:statusline_long_line_warning endif let long_line_lens = s:LongLines() if len(long_line_lens) > 0 let b:statusline_long_line_warning = "[" . \ '#' . len(long_line_lens) . "," . \ 'm' . s:Median(long_line_lens) . "," . \ '$' . max(long_line_lens) . "]" else let b:statusline_long_line_warning = "" endif endif return b:statusline_long_line_warning endfunction "return a list containing the lengths of the long lines in this buffer function! s:LongLines() let threshold = (&tw ? &tw : 80) let spaces = repeat(" ", &ts) let long_line_lens = [] let i = 1 while i <= line("$") let len = strlen(substitute(getline(i), '\t', spaces, 'g')) if len > threshold call add(long_line_lens, len) endif let i += 1 endwhile return long_line_lens endfunction "find the median of the given array of numbers function! s:Median(nums) let nums = sort(a:nums) let l = len(nums) if l % 2 == 1 let i = (l-1) / 2 return nums[i] else return (nums[l/2] + nums[(l/2)-1]) / 2 endif endfunction "statusline setup set statusline=%f "tail of the filename "display a warning if fileformat isnt unix set statusline+=%#warningmsg# set statusline+=%{&ff!='unix'?'['.&ff.']':''} set statusline+=%* "display a warning if file encoding isnt utf-8 set statusline+=%#warningmsg# set statusline+=%{(&fenc!='utf-8'&&&fenc!='')?'['.&fenc.']':''} set statusline+=%* set statusline+=%h "help file flag set statusline+=%y "filetype set statusline+=%r "read only flag set statusline+=%m "modified flag "display a warning if &et is wrong, or we have mixed-indenting set statusline+=%#error# set statusline+=%{StatuslineTabWarning()} set statusline+=%* set statusline+=%{StatuslineTrailingSpaceWarning()} set statusline+=%{StatuslineLongLineWarning()} set statusline+=%#warningmsg# set statusline+=%{SyntasticStatuslineFlag()} set statusline+=%* "display a warning if &paste is set set statusline+=%#error# set statusline+=%{&paste?'[paste]':''} set statusline+=%* set statusline+=%= "left/right separator function! SlSpace() if exists("*GetSpaceMovement") return "[" . GetSpaceMovement() . "]" else return "" endif endfunc set statusline+=%{SlSpace()} set statusline+=%{StatuslineCurrentHighlight()}\ \ "current highlight set statusline+=%c, "cursor column set statusline+=%l/%L "cursor line/total lines set statusline+=\ %P "percent through file set laststatus=2

Amongst other things, it informs on the status line of the usual standard file information but also includes additional things like warnings for :set paste, mixed indenting, trailing white space etc. Pretty useful if you're particularly anal about your code formatting.

Furthermore and as shown in the screenshot, combining it with syntastic allows any syntax errors to be highlighted on it (assuming your language of choice has an associated syntax checker bundled.