hey, guys, X360 USB Pro and X360 Key have played an important role in playing the Xbox 360 games. But i dunno the difference between X360 USB Pro and X360 Key, i google it and found http://blog.volumerates.com/cell-phone/do-you-ever-know-the-difference-between-x360-usb-pro-and-x360-key.html , if u dunno either, hope this will help u.

the X360Key is the world's first xbox 360 jailbreak item, with this item, you can play all of the xbox 360 games from your external USB drive or game hdd.

X360 USB Pro - USB - Sata, connects sata devices such as XBOX 360 DVD Drives to a PC

360 Key is a USB Device that will allow games to be booted from a USB Hard Drive instead of burning them to a DVDr+DL

Yeah as people have said, the X360 USB Pro is a device which enables Xbox 360 DVD drives to be flashed with Jungle Flahser via a USB connection without the need to connect the drive directly to a SATA port on your PC motherboard or to a VIA 6421 Card - meaning you can even flash your Xbox 360 DVD drive from your laptop.

The X360 Key consists of a motherboard and a key which emulates the Xbox 360 DVD drive by running a custom Linux OS and allowing .iso files to be booted directly from an external USB HDD without the need to flash the DVD drive or run custom firmware. It also promises to do much more, possibly homebrew style software.