These should not be skills.
I was a big fan of these types of skills for a long time (roll intelligence + perception, roll your spot, roll your observation check), till I listened to someone else play in a system with these skills.
"Roll your search," *clatter*, "You don't see any traps," "I open the door," "There's a room," "I search it for treasure and traps," "Roll your search," *clatter* "You don't see any treasure or traps," "I search the doors," "Roll your search," *clatter*, "you don't see any traps, the door is locked," "I unlock it," "Roll your open locks," *clatter*.
Is this fun?
I can come up with several objective reasons why it *isn't* fun.
First is the issue of spotlight time. Either one person has the search skill only (or has trapfinding, let's say) and dominates table time and yet all they are doing is rolling their skill over and over (see the second point). Or *everyone* has the perception-type skill and feels forced to train it over and over because of how important it is. In a system like 3.5 it becomes a skill sink on the non-thief characters; in non-level-based skill systems like Hackmaster, they spend all their time training it until it's up to an unreasonable percentage.
Second, the player has no input on the gameplay. The only time their decision making comes into play (their choices, or 'fun') is when they are leveling and they make the choice to increase the skill. After that it's just rolling at the table every time the DM wants to find out if you can see something.
Now, maybe some people enjoy using dice to reach a statistical mean while six people sit around waiting for something to happen. Maybe your game is a complex combat simulation where you go from fight to fight to fight in the course of an evening. I could see it being useful in both these situations.
I'll have three to six fights a night (sometimes as many as ten or twelve). we generally play for about seven hours, and we rarely spend more than two hours in an evening fighting. (And that was for a melee with around 100 participants. We've had 2 other long combats against groups of undead who don't fall down and die and can't be turned). Mostly we spend adventuring, exploring, and role-playing.
Here's the most important point I think. You don't need this skill. Either you tell them the information because you want them to know it, or you wait for them to look for the information. The whole play of the game is wrapped up in the interaction this skill serves to eliminate. "But what if they don't think of where to look?" "How will they know the trap is there?" Let me repeat myself.
The whole play of the game is wrapped up in the interaction this skill serves to eliminate.
It is the players job to notice these things. Take the Find Traps skill - it still exists in my game. We use it very much like a savings throw. The players tell me how they are moving throughout the environment, what precautions they are taking, etc. Then I describe what happens. They often prod ahead of them with a 10' pole, and they move slowly, mapping and examining around for traps. There was a flaming gas vent trap they avoided. . .
"The hallway ahead looks darker."
"Wait, why does it look dark?"
"You don't know."
"I check out the walls and floor, prodding ahead with the pole."
"You notice that the walls and floor appear to have dark stains on them."
"What kind of stains, I rub my finger along them."
"You see that the walls are covered in soot."
"I look closer on the tops and bottoms of the walls ahead."
"In the darkness you see several vents."
"We go the other way."
"Roll your search/observation/perception"
"I got a 17"
"Flaming jets burn you"
"Roll your search/Observation/perception"
"I got a 27"
"You find a trap"
There is a strong movement in modern systems away from the deathtrap. You know why? Because the players don't have any control of the game. In the way I run my game, if a player runs into a death trap it's because they did something stupid. Not because of random chance.