How to get more screen lock options? In my Nexus 4, I have the following screen lock options.

None
Slide
Face Unlock
Pattern
PIN
Password


How can I get options other than these for my lock screen? I prefer non-rooted ways to get this done.

(The option I prefer is what I have in my Jailbroken iPod Touch - AndroidLock XT that allows me to use an unlock pattern with the nine points to create the pattern, invisible. But I don't mind any other interesting options available for a screen lock on android)
To get a lock screen similar to the one available for Windows Phone,
try Lock Screen 7. 
WidgetLocker Lockscreen is a paid app which promises to give more lock screen options.
Quick Launch Social Lockscreen is another option.
Then there's Active lockscreen.
Holo Locker Plus and its free version.