The most likely thing is the PS is failing and has fried the USB.
Failing power supplies are common and can cause your symptoms.
Check your PS.
See response 4 in this:
http://www.computing.net/hardware/w...

Try disabling the USB controllers in the bios. If the mboard is fine otherwise with those disabled, a PCI USB 2.0 controller card is cheap to buy and may work fine.
If not you will need another mboard.

"could it be static electricity or some kind of power surge that happened as the metal made contact?"

The metal shell - outside - of the USB ports are grounded, and so is the case, as long as the cord to the PS/case is properly grounded, so static electricity could not likely cause that as it would be drained away immediately. A power surge or spike as you were attempting to plug in a USB device could cause that if your computer isn't plupged into something that adequately protects EVERYTHING plugged into the computer from that (including your cable that connects you to the internet, and your phone line if applicable, and all devices that plug into AC), or a lightning strike anywhere on your power grid near you can get past such protection, but that's not likely - defective PSs often cause damage or symptoms that defy logic.
.....

Or there's a tiny possibility your mboard has the bad capacitor problem.

Open up your case and examine the mboard to see if you have bad capacitors, and/or other findable signs of mboard damage .

This was the original bad capacitor problem - has some example pictures.
History of why the exploding capacitors and which mboard makers were affected:
http://members.datafast.net.au/~dft...

What to look for, mboard symptoms, example pictures:
http://www.badcaps.net/pages.php?vid=5
Home page that site
- what the problem is caused by
- he says there are STILL bad capacitors on more recent mboards.
http://www.badcaps.net/

Pictures of blown capacitors, other components, power supplies, Athlon cpu's, etc.:
http://www.halfdone.com/Personal/Jo...