My son (born Oct. 5th of 03) has two teeth on top and bottom (center ones) and is getting the two on both sides of the the top (canines?) anywho, I just realized that he "grinds" his teeth together during the day! What's that about? I've looked at them, and the tips/edges look a bit different in color (more white) and I'm just worried that he might chip them or wear them down. What can I do, is this normal, why is he doing it, anyone else having or had the same "problem"?

it's normal...my son did it for a while around the same age and grew out of it.
but mention it the next time you go in for well baby checks and the doc will take a look to make sure there is nothing wrong.
My son is 15mos.and actually just started doing this a few weeks ago. I dont know if something is wrong but it sounds common enough to pass this off as baby discovery.