What if items remained hidden until you passed within, say, 30% of your sight radius of them. So if you walked past a key on the ground, you would see the glint that occurs when an item is created and it would there-after appear when you pressed ALT. I just hate it that I can walk up to any locked object, press ALT and immediately know where to find the key to open it. It makes locked bonuses practically useless.
I agree that it helps for the lazy - I do it too. But it can't be that hard to click on half a dozen obvious locations around the locked object to see if you can find it. Those with lock-pick can give up and pick the lock. Those without lock pick can perservere for the key or give up. I have lock-pick (5) and have used it on about 4 things outside the theives guild because I can find all the keys. I've even found keys for some of the locked barrels! And none of it took any effort.
Perhaps this could be part of the difficulty setting. Easy and normal games could have the ALT key as it is now, but the Hard setting makes you look for things.