I noticed this sorta "squeaky" noise occuring while the motor is running, and can't quite put my finger on what it could be.

It sounds like a loose belt, BUT the belts are tight.
Any ideas what this noise could be, or be coming from?

BTW it's louder in the front of the motor, that seems to be the location of the problem.

 

Maybe the bearings in one of the accessories are going south (like the alternator)?

Spray a little water on the belt(s) at a few points while running and see if the squeak goes away for a few seconds. If so, it's a belt issue (worn out, not tight enough). If it's an accessory it'll make no difference. Or you could simple take the belt(s) completely off for a short run and see if that makes any difference. On old v-belt cars you could figure out exactly what accessory was squeaking by removing one belt at a time. With a serpentine it's all or nothing.