What is the largest GB that a USB Flash Drive come in?

I have seen a 32GB USB flash drive. On pricewatch.com they also have a 64GB one.
Of course, it comes with a price, too.

On tigerdirect.com there are a few 64gb's but the cheapest one is 129$ also if your looking for high storage capacity but portable try getting something like this Western Digital Black Passport Essential 250GB it's powered by usb

I have seen 160 GB usb flash drive and it's really costly...

You can find out a lot more about the different qualities of USB memory at this article (http://www.usbtalk.net/2009/09/nand-flash-chip-grades-explained/) discussing it. Pretty amazing that most people do not even know that there are several standards of quality for this medium.