[self.view bringSubviewToFront:myImageView];
Other relevant function:
– bringSubviewToFront:
– sendSubviewToBack:
– insertSubview:atIndex:
– insertSubview:aboveSubview:
– insertSubview:belowSubview:
– exchangeSubviewAtIndex:withSubviewAtIndex:
Bring Image or View to the Front
iPhone SDK Tips & Tricks