Use ido for *all* completion?

[Mark Plaksin]

Is there a way to use ido's magical completion for everything?  For
example, I'd like it to complete when answering the prompt M-x gives.

CVS Emacs finally broke lightning completion[1] for me so I decided to look
at ido.  I like it!  You can configure Lightning completion so that it
completes for all minibuffer prompts.  It would be great if ido did that
too.  Can it?

Thanks!

[1] http://www.math.washington.edu/~palmieri/Emacs/light.html  Hasn't been
updated since 2002.