Ok people, besides the noticeable differences like mouse form and CPU units, what are some of the things inside a Macintosh computer that makes it so "different" from windows.

CPU units? do you mean little-endian/big-endian?

Macs use openfirmware instead of crappy PC BIOS. OpenFirmWare is what people like Sun use on their workstations, it is much better (a standardized interface for one thing). There is also a free implementation of the openfireware in the works (that will rock).

Other than using a PPC and OpenFirmware macs are pretty much the same as your standard x86 box. You can even get "open" PPC boards in the ATX form factor and use them in your vanilla ATX case.

Yeah, HDDs, RAM [SDRAM I believe], are the same as the kinds used in PCs. Apples don't use floppy drives, any more, and I know the iMac uses a custom cd/rw/dvd drive, not sure about the note books. Also, I'm not sure what kinda sound card, graphics card, modems [I'm guessing controller based of some sort] they use.

But, they big thing about them not being 'IBM compatable' is that they use the PPC [G4, G3, ect], that's why Windows software won't work on Mac. I think at one time they used totaly different file [For images, movies, sound, ect] formats than Windows, but file formats have become more standardized now.

The sound is usually built in. Graphics cards in modern macs are either nVidia or ATi, depending on the model.

Macs use PCI and AGP, but, at least for graphics cards, you have to get the Mac version. Also they use a different keyboard port (at least used to until they started doing keyboard and mouse through USB).