Do I need to reformat the hard drive to install BootCamp?

if you have the latest macbook, it's already pre-installed in your os x, just use spotlight to search boot camp.

I assume the question was whether you need to reformat your hard drive to repartition it before installing Windows. The answer is hopefully no.

You should back up your hard drive just in case.

You might get the dreaded "some files cannot be moved. Please reformat your hard drive" error message. This is more likely to happen the more files you have on your hard drive, and the more you have used your MacBook before attempting to run Boot Camp Assistant. In this case, some people have reported success booting off the Leopard DVD to use Disk Utility from there to repartition the drive, the point being that Boot Camp Assistant is unable to move files which are in use on the startup disk. Said people then reboot off the internal disk, use Disk Utility again to unpartition the drive, then use Boot Camp Assistant to repartition and install Windows. Back up your hard drive first, but if that works, then you still didn't need to reformat the hard drive.

Finally, once you boot off the Windows CD to install Windows, the first thing you will be asked to do is perform an operation on the Windows partition. You do want to format the "C: Boot Camp" drive. If you choose the wrong drive to format, you will lose Mac OS. If you choose to not format (or if you choose to "convert") the partition, the Windows installation will fail. If you choose the correct ("C: Boot Camp") drive to format, Mac OS and your data will be unaffected, and Windows should subsequently install properly. Nevertheless, back up your hard drive first!

Are Parallels and VMware any good? Depends on what you want to do. Parallels (I haven't used VM Fusion, but I assume it is equivalent) is great for running Windows without having to leave Mac OS. But it uses lots of RAM and resources, and it doesn't take full advantage of your hardware. So if you need to do something intensive (e.g. gaming) you want to use Boot Camp. If you want to make sure your web pages render properly in Internet Explorer, you can probably get away with Parallels or VM Fusion if you have at least 2 GB RAM.

I don't claim to understand anything, but the point of the GUID partition scheme, which is now the default (or supposed to be, but YMMV) on Intel Macs is that it is possible to repartition without erasing the disk. You are right that traditionally repartitioning effectively deletes. I've also noticed that selecting the repartition tab in Disk Utility, even (I think!) for GUID partitioned disks, gives me the warning that repartitioning will delete the disk. So I don't know the procedure for using Disk Utility to repartition losslessly; I only know that I've read people here who claim to have done it successfully. This is also why I encourage you to back up.

I have experienced, however, that Boot Camp Assistant repartitions losslessly. And via the Winclone website, I learned that the diskutil Terminal command now has a resizeVolume option which purports to be lossless and so is surely what Boot Camp Assistant and--if you can convince it to use resizeVolume and not, say, partitionDisk--Disk Utility uses behind the scenes to nondestructively repartition.

Parallels and VM Fusion are probably less resource hogs than VirtualPC because VirtualPC was an emulator whereas Parallels and VM Fusion only have to set up virtual machines in which Windows can run natively.

However, if you set up a (default) 512MB virtual machine, then Parallels immediately grabs 512MB, plus whatever Parallels itself needs, which is why you want the large amount of total RAM. Also, Parallels will, I think, grab one of the two processor cores for the virtual machine, which means that Mac OS has to do with less. And Parallels has to emulate a BIOS for the VM.