@Roooney67
Welcome
1. You can't install Windows on a G4, so if you want to play Civ4 before you get your Mac Book you'll have to use the Mac version.
2. If you wait for your Penryn Mac Book then you will have three options: run the Mac version, or run the Windows version, in BootCamp or in a virtual machine. (Note it will NOT be a PowerBook - Apple dropped the 'Power' names when they dropped the PowerPC CPUs). Which option you choose depends on your objectives.
- The Mac version may or may not run at all on a yet-to-be-released Mac Book. I've no idea what the specs of a Penryn MB will be, or what graphics hardware it will include. Just about every new Apple graphics hardware release has broken Civ4 in some way. So that option's a complete lottery at this point.
- As far as I can tell, Parallels isn't slow, Parallels has been benchmarked as being as fast or faster than Bootcamp when running WinXP. I just see some graphics problems in Civ4 - missing faces, flashes of the full map at start-up ... I get away with running in a Parallels virtual machine because I don't actually *play* Civ4, I just try to support people who play GOTMs. If I did play it, I'd probably get annoyed by the graphics limitations under Parallels.
- BootCamp is the safest bet, as you will be running the original Civ4 software on a high performance Windows PC under your choice of XP or Vista. The bad news is that while you are doing so you don't have access to Mac OS X.
@MotezumaMan: What was your question again?