Originally Posted by MovieMan
As a fan of the upper deck, I must add that if you're sitting up there and your carry-on won't fit in the overheads, the crew will gladly store it for you. Of course, that does mean you'll have to take out whatever you want to keep with you, or it will be somewhat more difficult to get if you need it in flight.
Or, you can nicely ask the crew to have it stored last in the storage area so that you can retrieve stuff easily when you need to.