Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Well, it's not a studio quality microphone or anything, but I've gotten pretty good performance out of the microphone on my old iBook G4, and my currently owned imac and Macbook Pro.

Here's a few things you can try:
Go to System Preferences and go to "Sound". Click on the Input tab and decrease the input volume for your microphone. It might help reduce background noise. Another thing you can try is checking off the "Use ambient noise reduction" box if it's not already checked.

Note: I'm still using 10.4.11, so if you're using Leopard (which you almost certainly are if your macbook's brand new) then I'm not sure if your system preferences will have exactly the same options.
 
It's still not exactly what I would expect, but reducing the volume a bit and turning on the ambient sound reduction helped a lot.

Thanks!
 
This is kind of odd.

After doing all the volume stuff, I could still hear the piiiiiip noise in the background. It wasnt bad. But definitely still there.

Then, for a reason I don't remember anymore, clapped my hands next to the mic...and now it seems near perfect. Does that make sense at all? haha
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.