I've also been discovering the wonders of high res music files on a USB Flash drive; the Oppo will play music in 4 different ways: by disc, USB, E-sata (hard drive), & streamed over a network

Two other notes: in theory you can network the device with the right kind of hard drive, although again this involves a computer or some other way to sort through directories

Your only easy option is to connect an external hard drive or USB memory stick

There seems to be some thought that an advantage to playing files with a USB port is a reduction in timing jitter due to the lack of a spinning disc (or hard drive).I haven't done much redbook cd listening due to time constraints

The interface for playing high res files from USB sticks and hard drives is fine for me (not that iTunes would not be nicer)