Is it necessary for a 4 port?
These 4 and 7 port USB hubs are perfect for connecting a variety of USB peripheral devices to your USB Mac or PC computer. You can now connect joysticks, printers, modems, scanners, cameras and even other USB hubs via this easy, flexible USB technology. The FriendlyNET Home USB Hub series has over-current protection to prevent one device from draining power from the other users on the hub. Auto-partitioning - the FriendlyNET Home USB Hub 4 and 7 will isolate a malfunctioning port or device to prevent interference with other devices on the hub. The USB hub supports dual power mode meaning the hub can be powered by either the computer itself (bus mode) or via the included power adapter (self powered mode).
http://www.us.buy.com/comp/product.asp?sku=10217900
Also do I have to buy any other cable for any USB hub?
These 4 and 7 port USB hubs are perfect for connecting a variety of USB peripheral devices to your USB Mac or PC computer. You can now connect joysticks, printers, modems, scanners, cameras and even other USB hubs via this easy, flexible USB technology. The FriendlyNET Home USB Hub series has over-current protection to prevent one device from draining power from the other users on the hub. Auto-partitioning - the FriendlyNET Home USB Hub 4 and 7 will isolate a malfunctioning port or device to prevent interference with other devices on the hub. The USB hub supports dual power mode meaning the hub can be powered by either the computer itself (bus mode) or via the included power adapter (self powered mode).
http://www.us.buy.com/comp/product.asp?sku=10217900
Also do I have to buy any other cable for any USB hub?