My first thought was water pump, but that didn't sound like my water pump when the bearings went out on that. I didn't get chirping, but like knocking sound. I could see the pulley wiggling slightly side-to-side.
Try watching the pulleys with a flashlight, see if any wiggle as the engine runs.
With the engine off, try grabbing the pulleys and wiggling them. The belt tension makes this difficult, so you can remove the drive belt first. See this post on my water pump replacement thread
for removing the drive belt. In short, jack the front of the car up, support on jackstands. Take off the front passenger tire, then the plastic panel behind the tire. Use a 14 mm wrench on the tensioner pulley to loosen the belt, and jam a 5 mm allen key into the pulley to hold it with no tension. The belt will now slip right off.
With the belt off, you have access to all the pulleys. Grab them and try to wiggle them. If they wiggle, or if you spin them and they are rough, and don't spin smoothly, the bearing is bad.
The water pump pulley should spin smoothly but will have a lot of friction, so it won't keep spinning after you let go. The idler and tensioner pulleys should spin freely and continue spinning for a bit after you give them a quick spin. The AC pulley may have a tad of friction from the clutch but should still spin smoothly. None should be able to wiggle, at least not more than a hint.
also be the belt slipping just a little? Check the condition of the belt when you remove it. If there are any cracks or it just appears old and dry, replace ti.