Usually under the sink in the kitchen next to the recycling container. If the bag gets full before I'm ready to go to the UPS outlet, I just put it in the trunk of my car. I order a few recycling bags at a time so there's always an empty one available.
That'd be ideal. All that real estate in my place is spoken for.
I'd have to do what Inked does - move it to the garage where an interim recycling tub already sits, so it wouldn't be to bad.
House probably does 8-10 large cups a day, so every 10-20 days I'd have to make a run, or just dump it in my own trash and pay the freight.