USB flash drives were invented by Amir Ban, Dov Moran and Oron Ogdan, of the Israeli company M-Systems, who filed US patent 6148354 in April 1999. There is a rival claim. Released later the same year, IBM Patent Disclosure RPS8-1999-0201 from September 13, 1999 by Shimon Shmueli accurately describes the USB flash drive. IBM partnered with M-Systems to bring the product to market.

More Info: en.wikipedia.org