Almost every PC accessory like keyboards and electronics like MP3 players connect to your PC with USB 2.0 ports, but I notice a lot of computers only have 2 USB 2.0 ports or less on the front of the PC. The back of a computer usually only have 2-4 USB ports on many computers.
However, these days almost every thing like game controllers for computers, MP3 players, Video players, cellphones, digital cameras, and flash drive use USB plugs to connect to your computer.
Unplugging and replugging in USB devices can be a hassle unless you have a USB 2.0 hub which splits one USB port into 4 or more.
I find using a USB hub also can make organizing my USB cables, flash drives, Digital cameras, etc better since I know they are all plug into one USB hub.
Plus, some USB hubs look so cool and cute.Yet, they are so functional when it comes to increasing the number of USB ports you can plug into your computer at once!
Another advantage of a USB hub is it prevents damage to your regular USB ports since you will be plugging your USB electronics into a USB hub which cost less to replace then hiring someone to replace the USB ports on your computer case. Many USB hubs also have over-current detection and protection which protects your computer from using too much current from your computer.
I also find using a USB hubs more ergonomic since I notice I don't have to crawl on the floor to plug in a USB plug in a port since I can place the USB hub anywhere I want to as long as the USB cable is long enough.
I recommend getting a USB hub with a long USB cable, so you have more flexibility where you put it.
If you mainly plug in flash drives, MP3 players, and low powered devices or uses its own power adapter you plug into a power outlet or is battery powered like a Digital Camera. A USB hub which does not come with an AC power adapter will work on your computer. A portable USB 2.0 hub with a short cable will also be a good choice if you use it on your laptop since carrying around a USB hub with a long cable while you are at the library can be a hassle. Plus, the USB cable won't get tangled.
However, if you plug in high powered devices like USB portable hard drives, and use your USB hub mainly on your desktop. I recommend buying a USB 2.0 Hub with a long cable and comes bundled with an AV power adapter. This will prevent you from drawing too much power from your computers USB port. With a longer USB cable, you can put your USB hub farther away from your computer if you like as long as the cable is long enough.