I believe it is a standard usb mobo 8 pin connector, although i'd have to look inside my case to be sure.  I'll do this when I get home to satisfy my own curiosity. 

 

Not to be nosy or anything, but why on earth would you need more than 8 USB sockets?!? 

 

As an added suggestion, USB 2.0 PCI cards are dirt cheap.  I've actually got a slightly used one I'd be willing to part with for shipping and handling charges.

Since the E520 comes with only 2 PCI slot I want to save them for TV card or Sound card. I have some USB brackets laying around so I was curious if I could use one of them.

Wouldn't the bracket take up a PCI slot anyway?

Yes it would. I used the PCIEx1 slot since nothing is going there. I tried last night and it works. The back USB ports on my comupter are all used up by wireless keyboard & mouse, ipod, 2 printers and 2 usb drives. Thats why I was looking to use the onboard USB port. Thanks.

There's some devices available for it (sound cards, video cards, tv tuners etc) but at this point in time they just aren't good enough to bother installing.

Good to know it works.  I should have realized you'd be using the x1 slot, since there's not many cards that are worth getting for it at the moment. 

Yep, I wish there was a choice to choose between a PCIEx1 or PCI slot when I order the PC. I can't find any use for a PCIEx1 slot.

You could also try fitting one of these:

 

http://catalog.belkin.com/IWCatProductPage.process?Product_Id=278295