I've seen a lot of setups with MH or suspended flourescent lighting, where the cover material covered the entire tank except for where there was heavy emergent growth. Fish are less likely to jump there; I don't know wether the plant stalks and leaves simply provide a physical barrier, they calm the fish enough to prevent jumping, or fish instinctually avoid jumping when they aren't in open water. The small constrained hole the plants must grow through also gives an appearence of growth literally spilling out of the tank, which is really something to see.