I looked at Howstuffworks.com, but their info on USB didn't explain a lot.

1) Looking right at the place where you plug devices in: There seems to be 2 strips of metal at top, 4 in middle (with plastic sheath), and 1 strips of metal at the bottom. Now what purpose does the 2 metal strips on top and bottom serve? What is the power sent through?

2) My PCMCIA slot is right next to the USB port (they are at right angles to each other). Is it ever the case where the USB port is just part of the PCMCIA slot?

3) Does the whole metal box part usually pop out of the front of the computer somehow?

USB is similar to a serial port. It comes with a pin to send data and another pin to receive data. The data is serial. The other two pins is for DC power. The DC power is about 5 volts. The metal around the USB connector is for grounding usually to shunt static electricity or ions. Go to usb.org for more information. Also go to http://en.wikipedia.org/wiki/USB.

PCMCIA and USB are separate connections. They are not connected to each other. PCMCIA connections is just a PCI connection for external devices. You can use PCMCIA to handle PCI cards using a bridge chip.

Please explain.