Found a solution (have not tested)
ETA: This still requires a hub (basically a router). Which is not practical for a mobile application.
Cables Unlimited USB-WIRELESS Dongle Set (Black) (http://www.wireless-usb.eu/index.php?c=WUSB060&n=14030861&i=B001GV00ZM&x=Cables_Unlimited_USB_WIRELESS_Dongle_Set_Black)
(http://ecx.images-amazon.com/images/I/41GZUg0lLIL._SL160_.jpg)
(http://ecx.images-amazon.com/images/I/51SHQhO7rLL._SL500_.jpg)
Brand: Cables Unlimited
Category: CE
List Price: $99.99
Buy New: $39.99
You Save: $60.00 (60%)
Color: Black
Media: Electronics
Memorabilia: No
Shipping Weight (lbs): 0.6
Dimensions (in): 8.5 x 6 x 3
nv:Cable Type: Wireless USB Kit
MPN: USB-WIRELESS
Model: USB-WIRELESS
UPC: 724580321620
EAN: 0724580321620
ASIN: B001GV00ZM
Features:
• Upgrade any existing USB device to Wireless USB
• Windows Vista/XP support
• Brings Wireless USB connectivity to a range of devices, such as hard disk drives, printers and hubs
• Connect to a USB Hub to use multiple USB devices
Editorial Reviews:
Product Description
Cables Unlimited's Wireless USB dongle kit allows you to upgrade any existing USB device to Wireless USB. Consisting of a pair of Wireless USB dongles, one for the device and one for the PC. This solution brings Wireless USB connectivity to a range of devices, such as hard disk drives, printers and hubs. Brings Wireless USB connectivity to a range of devices, such as hard disk drives, printers and hubs Connect to a USB Hub to use multiple USB devices Upgrade any existing USB device to Wireless USB USB adapters to accommodate any USB device connectivity requirements Windows Vista/XP support