Okay, this is a bad idea if your files are prefixed with ~.

(add-hook 'ido-setup-hook
 (lambda ()
   ;; Go straight home
   (define-key ido-file-completion-map
     (kbd "~")
     (lambda ()
       (interactive)
       (if (looking-back "/")
           (insert "~/")
         (call-interactively 'self-insert-command))))))

But if they're not, this keybinding lets you even more quickly reach your home folder when in ido-find-file.

It doesn't matter if you're a million directories in, just press ~ to go home.