Not sure if the D80 can use the same remote as the D70s, but I've got a genuine nikon remote the ML-L3. The cheap wireless infrared remote that only has one button. And in bulb mode the shutter will stay open as long as you want it to. Just press it once and it opens, and the next time you press the remote button it will close.
i used the same remote on my d80 and i'm pretty sure it worked the same way.
D800e l V3 l AW1 l 16-35 l 35 l 50 l 85 l 105 l EM1 l 7.5 l 12-40 l 14 l 17 l 25 l 45 l 60 l 75 flickr