Back on point, would it even be physically possible to have one that small? The USB3 controller on my motherboard isn't actually small and I believe my Patriot supersonic is "quad channel" so I presume it needs more than one NAND to do that?
Physically only enough room for two TSOP chips one on each side, so I assume it uses two x two die NAND modules to achieve quad channel.
So yeah, no point in trying to find a USB 3.0 drive that tiny, as there won't be enough NAND channels at that size scale to saturate USB 2.0 let alone take advantage of USB 3.0. Even if a BT receiver size USB thumb drive was USB 3.0, you still wouldn't get more than 10-20 MB/sec from it due the single tiny flash chip it would have to be using.
http://www.newegg.com/Product/Product.aspx?Item=N82E16820235063
Reviews indicate it's a) slow and b) prone to thermal failure due to the size, and seems to be a consistent theme with microscopic size USB flash media in general.
My Supersonic with it's large aluminum shell gets HOT after a few minutes of sustained 80 MB/s writes. If there was something the size of that Store n Stay that fast, it would no doubt melt itself.