I think the most I have read at the same time were 13 books, but that was at a time before I had an e-reader so there were literally 13 books lying next to me and I dragged them around the flat and the house. That was just crazy cause I also forgot where I left them, all scattered around like that. =P

Small stacks are better... but that e-reader is so easy and tempting to have more books. =P