To access USB Host mode on the Touchpad (to plug in a Keyboard/USB Drive/etc), you need:

1. A microUSB to USB Female cable (USB-OTG cable), available on ebay for ~$3, shipped [search 'USB-OTG cable']
2. A powered USB Hub (a USB Hub with a spot to plug in an external power supply), available on ebay for under $10, shipped, with power supply  [Search 'powered usb hub']

Although this is an article on hardware, I'm going to be using software to probe it. This is from a 32GB HP Touchpad, though the 16GB should be the same, barring the difference in storage.

/proc/cpuinfo: