Again, I must have a good group of players as they don't go around Taking 20 everytime they enter a room.
Maybe it's because they know that if there is a trap it'll be in a logical area and there is usually some clue that there's one there. Once they think there is a trap, they may Take 20 then, but it's usually in a focused area so it doesn't take too much time.
As for secret doors, they don't normally look for them either until they've got a better idea of the layout of the dungeon and thus get a better idea of where to look.
Sure, they do searching at other times, but it's rarely a "Let's search this room upside down Taking 20" type searches.
Now, I'm sure if I placed a lot more traps and tons of hidden doors and stuff, that attitude might change. I don't, normally, put in a lot of traps because most dungeons are homes to intelligent creatures and too many traps would be a nusiance to them. Also, if I go through the trouble of placing an item in the game, I normally want the PCs to find it so I don't make it too, too hard. But that's just me, and I'm sure others will disagree, but we've been having fun with it.
IceBear