This Thin Card drive from Taiwan manufacturer, ITRI, can hold from 16GB to 2TB in such a small form factor. It is USB 3.0 ready. However, the sad thing is that you cannot buy it yet.
Just a note. The video you are going to see will not show you a 2 TB Thin Card Drive. It is just 16GB. However, if you read the information from that video (on Youtube), you will know that it is capable of reaching the 2 TB size. Here is the video.