A more useful statusline in vim?

Question

I’d like to make my statusline in vim more informative and interesting, and for that I need some ideas. How did you customize your statusline?

Answer 1

Edit:-

Note vim-airline is gaining some traction as the new vimscript option as powerline has gone python.

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Seems powerline is where it is at these days:-

Normal status line

Customised status lines for other plugins (e.g. ctrlp)