[ame=http://www.youtube.com/watch?v=_KXHu9sTC2s]hay accumulator - YouTube[/ame]Ha ha ha ha! Around here it's about what you all are saying, 4x4 take about 400 to 500 lbs and 4 x 5 run about 900. Squares are usually 40lbs so the math is easy. Some guys bale really light or heavy but that would be a good average. I don't do hay but have lots of pals who do and they get 2 cuts, with the 2nd cut being about 40 percent the yeild of the first. Depends widely on what you're growing though and how you treat the field. Some dairy guys get 3 cuts of alfalfa every year but they fertilize a lot, reseed regularly and the last cut is way small compared to the first.
The big squares are coming into favor now, usually 800 to 900 lbs. I've never seen a bale handler system in action for small squares, sure would be neat to see.
You can have a video sent of this one in action. meanwhile, here's some pics: Hay Master, Inc.