Just weighed my bike. The scale reads 19.8kg which is approximately 43.56lb using the divide by 2.2 method.
It's a Carrera Subway 8 with a aluminium rack, rackbag with multitool, change of clothes, PRK, wallet, keys and phone, all my lights (one of which is a Smart 2x10watt halogen with a bottle sized battery), half a litre of water, cycle computer, airzound, Shimano Nexus 8 hub gears (not the lightest).
I commute with this bike and I can leave the town traffic behind. I live in the Pennines and although it may be easier to climb the hills where I live with a feather-light machine, I suppose the extra effort does me good.
Plus, going downhill is great.