the mysterious squeek

alright I have been on this caper for the past few days, and I am still baffled by it. yesterday I planned to attack the squeek with a can of silicone spray, and WD-40, but to my suprise it did'nt show itself when I turned my car on... so I decided, well maybe it'll come back later, and I put the 2 cans of lube in the trunk to use later when it appeared again.. and just when I got to work, and stepped out of my car the small squeek was back. I popped the hood, and looked for the elusive squeek, only unable to locate it... I checked the timing belt, the Ac drivebelt, and the alternators drive belt, but all sounded normal, it was coming from the other side of the engine, but I can see no moving parts on that side of the engine, at least none that are exposed, or not covered up by a cover. can somone help me pinpoint this annoying bugger? it's not noticeable from inside the vehicle, but you do notice it when you are outside standing next to it, while idling..

do you have an aftermarket intake on it ?

nothing in the engine bonnet has been modified... Just did an oil change, and new air filter in the oem airbox..