Not sure if the OP only wanted a USB flash drive but I noticed the
Maxtor Black Armor 160Gb USB hard drive is on sale at Staples starting tomorrow. I had to look on the spec sheet to see that the full-time whole disk encryption is indeed AES.
Hardware-Based Full-Disc Encryption
Prohibits access without a password, no exceptions—not even a professional data recovery service can access the data without the password
KeyErase™
Permanent removal of encryption key allows secure redeployment of the drive