Remap :W to :w for lazy shift finger saving

Not an editor command: W got you down?

Put this in your $MYVIMRC:

cnoreabbrev <expr> W ((getcmdtype() is# ':' && getcmdline() is# 'W')?('w'):('W'))

Source: http://stackoverflow.com/questions/3878692/aliasing-a-command-in-vim

Note: Not sure if this will break other commands or not, but has been safe for me.