Sure!
There are two different ways to access the UIWindow objects currently being used by the application:
Code:
[[UIApplication sharedApplication] keyWindow]
This will return the currently "on top" window, (technically, the one that was most recently told to display itself) and is probably the only one you'll need for a simple application.
For anything more elaborate though, especially if you know you'll be using more than one window, you can use:
Code:
[[UIApplication sharedApplication] windows]
Which will return an NSArray containing all the UIWindow objects currently "owned" by the application. Happy coding!