Uhh, I love answers like: dont hit the key. That is no solution.
ah ... why not? whats the difference between "not hitting the ALT key" and something like "unbind ALT key to not show things when pressed"?
is there any mysterious dark power that forces you to press the ALT key? if not, then, well ... as long as you do not hit the ALT key you will not be shown things lying around which - by coincidence - is exactly what you are asking for, isn't it?
Again, I suspect the OP simply wants to be able to hold down the ALT button to help spot loot that's dropped after a battle (or items he himself has tossed on the floor) without it also revealing everything hidden around him in the process.
Since everything revealed when holding down the alt key is tied to your character's perception, rather than peppering the screen with text labels it might have been nicer to see a small, pulsing twinkle effect on areas worth inspecting, and perhaps the label only appears when you mouse over it for more information.
