I am here to tell you that you can in fact charge 4 items at once with a simple USB hub. This is my set up. While it is not pretty it functions well. You can always put it in a pretty container if you like. The best part about this enclosure is that I did not have to make it.
You will need (this is what I used, if you use a different hub or power supply your mileage may vary):
1 Hand Drill and a stepped drill bit or drill bits of the appropriate sizes.
1 USB hub with a power supply that is 5V/2.6A
1 Neato box to put it in
Step 1: Start by Drilling a Hole at Your Access Point for Your USB Cables
Yes this box is ugly but it was again something I had sitting around and I did not have to make it.
Here I used a stepped bit and made the hole 3/4". This makes it easy to feed the USB cables through it. You could go 1/2" and feed the cables small end in first. I drilled my hole right in the middle of the bottom of the box, why? Because I can.
Step 2: Get a Standard 4 Port USB 2.0 Hub
I would not recommend using one of those switched USB hubs from eBay. I have had 2 out of 3 fail, they are just not worth the effort and waiting time. I bought my hub at Office Depot for $7 US and the power supply (5V/2.6A) was one I had left over from a dead component. THIS is why I never throw away power supplies from anything even if it has a plug I may never use. I can always wire it with a new plug later.
Step 3: USB Hub Mounting
I mounted my hub externally because mine does have a tendency to be flaky on the power because the power supply is a generic 5V 2.6A supply. I may hard wire it in at a later date. I drilled two 3/8" holes to run my 12" Zip Ties through. I could have made it with one but it would be too close I think. You can add one Zip Tie that goes 90 degrees of the main ones to keep it from moving around, but it must be a thin one so it does not block the charge ports.
There are literally hundreds of ways to mount your hub, this is just the way I did it. The hub does not get hot so air flow is not an issue.
Step 4: Anchor Your Cables
Because this is a dedicated charger I just mounted the cables in a permanent fashion. I have dozens of these cables floating around so this is not an issue. You see I used a hammer in anchor for the power and a zip tie mount for the USB cables. If you look closely you will see that the power cable is coming out. I later had to add two screws on the opposite side to keep this from happening.
For the Zip Tie mount I put a screw in it because the mounting tape would not hold to this wood no matter what I cleaned it with.
If you plan to use this with devices that have different cable types this is the time you want to make sure you have the proper assortment in the box before you anchor your cables down. For mine I went with nothing but micro USB for 3 ports. I intentionally left the 4th port open so that I could use it for a different connection cable in the future if needed.Or you can do like I am doing and leave a port open and buy a 10-into-1 plug like the one in the photo and be a charging god.
Step 5: Clean Up the Install and Make a Harness
I like to zip tie all similar cables in an install just to make it neat. I also use white Zip Ties where it really won't show. For whatever reason white zip ties are cheaper from my supplier than black ones. At this point you can even put a harness sleeve on the cables to clean it up even more.
Step 6: You Are Done!!!
Here you see that my station is charging 3 devices. This is a Samsung S3, Samsung Galaxy Mega 6.3 (biggest battery on the market - also a power hog when charging), and a ??? LG flip phone.
As a side note my hub did not light up the power light. I am sure this has something to do with the fact that it is not plugged in a computer. Because the devices have easy access and I can see if they are charging just by pushing the home button I don't care that there is no power light.
Later on I added my Nexus 7 2nd Gen to the group and all were charging just fine. Splitting up the power like this does not seem to affect charging times.
Side note: I am pretty sure your PC would not like this if you plugged it into this. My brand new 8 core with a ASUS mobo makes the USB port flaky when plugging and unplugging devices. Could be that the hub is best suited for charging.
This is my first Instructable so feedback is welcome and appreciated. If you have something different you would do please add to this in the comments.