I would like to have the ability to speicify which layer I am trying to label with the label tool. As it is now, if I have a lot of layers turned on and I want to label features that are beneath features of another layer, I have to first turn off those other layers before I can place my label. If I could specify the target layer I am trying to label, this would no longer be an issue. A simple drop-down list (similar to the one in the Identify Options Window) that gives me a list of visible layers would easily fix this problem. See the mock-up below.