Is there an way to make an invisible UIButton that will still “be there” and catch touch events for my UIImageView?

You should be able to set the button’s ‘Type’ to Custom in Interface Builder, and it will not display any text or graphical elements over the UIImageView. This way, you don’t need to adjust the alpha. If the view is built from code, use:

button = [UIButton buttonWithType:UIButtonTypeCustom];