There are several places where someone could purchase a USB to parallel port adapter. Stores such as Office Depot and Staples both sell the USB to parallel port adapters.
The only parallel to USB adapter I've seen is one which allows you to hook up a parallel printer to a USB port on the computer. You could not use that manner to create USB ports.
To interface a parallel printer to a USB port, you need a USB Parallel Printer Adapter, Belkin makes a reliable one that I have used for years.
There are a number of retailers that sell a Firewire to USB adapter. One can purchase such an item from Amazon, ebay, Maplin, Staples, Walmart and Best Buy.
There are several websites one may purchase a wireless USB adapter. Some of these websites include eBay, Amazon, Walmart, Best Buy, Newegg, and Target.
There are various places one could purchase a Bluetooth USB adapter. For example, Amazon, Viking, Ebuyer, Uk Cellphones, Impact Computers, Ebay and Dino Direct.
There are many places to purchase a USB wireless adapter. It depends if you want to purchase one online or in store. Best buy has many options to choose from, both online and in store.
One can purchase a wireless g usb adapter at an electronic and computer store. Online Amazon and eBay offer a wide selection. Locally Walmart, Target and Best Buy all have this item for sale.
If you do not have one, you can purchase usb bluetooth adapter.
You can purchase a USB hard drive adapter online through websites such as Tiger Direct and New Egg. You can also purchase one from personal sellers through eBay and Craigslist.
You can buy one from the camera maker's website. You can also find some at amazon.com, or ebay.com.
There are a host of different places where USB AC adapter are available and can be purchased online. It's always good to have an extra USB AC adapter. Electronic special stores like Radio Shack are also a good place to find the right charger for you.