I paid almost 100 bucks for the ultra fast micro 64 gb sd card for my surface tablet.
Its as fast as the internal ssd.
I had a 64 gb usb thumb drive not work on my surface tablet or epson wifi printer. It was a kingston data traveler model. I ended up using it as a readyboost drive for my win 8 pc.
I want to setup a "cloud" in my car with a wifi router so I can access extra stuff at work or home as my car isnt too far behind me. I know you can buy some wifi memory storage devices, but they are limited in size.