Putting the mysteries to rest
Firstly, to clear up the MacBook confusion: There are 5 magnets in the display assembly of the MacBook as it stands. 2 in each corner of the display assembly act as the magnetic latch which holds the display closed (Apple call these the "display magnet pairs"). The fifth and final magnet is vertically in the middle of the assembly, to the left of the LCD panel. This is the sleep magnet which enables the MacBook to know the lid is shut and it should now go into sleep mode. There is no magnet in them which is designed to hold the Apple Remote to the unit.
Now, the iMac's: The new iMac's do not have a magnet on the inside of the front bezel as the previous generation iMac's did. There is no magnet in them which is designed to hold the Apple Remote to the unit. There are 14 magnets in the machine (sam with both the 20" and 24" variations), all of which hold the glass panel in place. 4 are on the top, 4 on the bottom and 3 on each side. These are the only magnets not built into components (such as the hard drive) in the new iMac Mid-2007. So no, there is not a magnet for designed the Apple Remote.