something to keep in mind, by putting stuff on your bed you may be damaging your comforter. If you are using down or some of the great, but expensive, sythetic fills, you should not put anything on them (unles you are OK with damaging the fill)
(simple solution is to just gently roll the comforter back, and place items, on a tarp or something, on the sheets (not on the comforter)
not a big deal if you use a $100 comforter, but for those who have spent a couple hundred on a nice comforter....