Auxiliary Data in custom view?

FROM : Rick Mann
DATE : Thu Nov 22 22:57:10 2007

In my Carbon app, my custom view had "Auxiliary Data" that I could set 
in IB, and then get at in the code. I used this to name a background 
image to display. My view would then load that image and display it.

Is there something similar in Cocoa?

Alternatively, what's the way to display a background image in my 
Cocoa custom view?

--
Rick