Colla, that’s true, with Vista/Win7 you can “grow” or “shrink”, otherwise known as resize partition as you like and then in to free space you can create additional primary partition/extended partition+logical drive.
But to do so, first you need create a partition, to resize something you need actually have something to be resized.
And to make any OS understand disk/partition beginning point and end point, you must create partition for certain file system.
It does not matter what file system you using, is it: NTFS, FAT32, Razor, EXT2, EXT3 (last 3 are Linux/Unix file systems). Always partition/partitions first, before formatting.
Exception is RAID, to make RAID controller understand, what to do with disks. First you have tell to RAID controller, how use disks. AKA create: RAID 0, RAID 1, RAID 0+1. etc…
And after that create a partition for a certain file system and format for a certain file system.