How do I change the login screen colour or background in Windows 7?

I'm running Windows 7 Home Premium at home and Professional at work.

How can I change the colour and/or the background image of the lock/login screen? I'd like to set it to something nicer than the default blue with flowers.


We actually have a great article on the Super User Blog by studiohack about this!

Bored with your login? Hack it!

It's a bit lengthy, but gives you MANY ways of changing it - some are programs, others use the registry.