I was outside in the drive way and saw what looked like a lowflying helicopter.It was around 9 at night.It was very bright.I noticed there was no sound and it seemed to be just over a mile away.It would go up high with a very obvious wobble back and forth then hover a bit then fall back down quickly.It would skim along the tree line.What made me wonder about it was the movement,Ive never seen anything move like that.It was not an airplane or helicopter,they just dont move like that..I came inside after watching for 5min (I was having a smoke) and went upstairs and told my girlfriend that there is something really wierd outside.We opened the window and both observed it for about another 20 min or so.I tried to get a better look through a 35mm camera but couldnt see it clearly.I went back downstairs to grab the binocs from the car,when I got back to the window I saw it briefly behind the treeline then it just went away.A roommate saw the same thing a few days prior to last night.This went on for about a half hour from the time that I first noticed it.I know we both saw something very odd and cant possibly be the only ones due to the low alltitude and early time of night.Im wondering if anyone else in the area has seen it as well.Because it couldnt have been just me and my girlfriend no way.