Laptop makes a clicking sound

Read these:
Problem with hard drive clicking - ThinkWiki
The official Hard drive clicking noise thread

What you're possibly hearing are head load/unload cycles.

Get yourself a tool that can monitor the SMART state of your drive and keep an eye on the load cycle count when the drive clicks. If you can see an increase of these values when the click comes, well, then it's a normal load/unload cycle.

You can tweek PM and AAM so that the clicking sound happens not that often, but that will probably increase power consumption. I also had a lot of clicks with my Samsung drive in the laptop and after some tweaking of the options I'm down to a few clicks a day, which mostly happen while I'm not at the machine.

Jam it back in, in the dark.

@packrat: Any reason for dissing my post or are you just in a bad mood?

How ya doing, buddy?

The sound of an unload/load cycles strongly depends on the drive brand and on many more factors. It can range from a low tick sound to a loud clank-like sound.

I also want to point out that everything that is written by you guys here is pure speculation, while monitoring the SMART values is giving you actual (real!) information where the sound is coming from.

If a system is making sounds that are odd, then one should not guess where they come from but find the true source.

From your profile packrat: "Interests: SCIENCE!, math, ..." <- science and math are based on proof. And checking for coinciding clicking sounds and increasing SMART values is a pretty good proof if you ask me.

EDIT: To add some more. If there is no correlation between the clicks and the SMART values then of course this doesn't prove anything and we're back to knowing nothing. Next thing would be removing the harddrive and stressing the system from a livecd (Knoppix -> CPU benchmark to heat up the system), doing some warming-up/cooling-down cycles and observing if the clicking sound can be triggered this way. You can also try booting from a live-usbstick, so you can also remove the optical drive (which might be also responsible for clicking, however I highly doubt that - plus you also ruled that out). With most mechanical parts removed then this leaves some more places where to look: the cooling system itself (maybe clean it?)
If it's neither the mechanical parts like the drives nor the cooling system then I opt for packrat's explanation, but only then.

This thing is sticky, and I don't like it. I don't appreciate it.