I'm with Dude, I keep all my tanks either fairly close to a window (not in the window, but next to them), or near to a sink or a bathtub because that way I don't have to empty buckets. :)
Oh, and aging the water is a sometimes alternative to putting in water conditioner. (the chlorine evaporates after a few days) But, to do this, you have to make sure you don't have chloramine in your tap water. If you do, then you'll still need to add conditioner. Beyond that, if you use the water straight from the tap, I just get it to the right temp for what's already in the tank, fill up my jugs (I keep the 5g water jugs for filtered water just for this purpose), add my conditioner, let it sit for 15-20 mins, and then put it into my tanks.
But, it doesn't hurt anything to age the water, and if you have trouble getting it hot enough, the heated tub sounds like a great idea. :)