A simple UIView that draws itself in a color based on its address in memory.

BlahView.m

@interface BlahView : UIView
@end


@implementation BlahView

- (void) drawRect: (CGRect) rect {
    CGRect bounds = self.bounds;

    UIColor *color = [UIColor colorWithRed: (((int)self) & 0xFF) / 255.0
                              green: (((int)self >> 8) & 0xFF) / 255.0
                              blue: (((int)self >> 16) & 0xFF) / 255.0
                              alpha: 1.0];

    [color set];
    UIRectFill(bounds);

    [[UIColor blackColor] set];
    UIRectFrame(bounds);
} // drawRect

@end