"How do I use tether through my BlackBerry for my Xbox 360 with no computer involved? I have the USB cord for the BlackBerry and directly plugged it into the Xbox 360. I don't know how to get the Xbox 360 to read the BlackBerry connection."
Attempting to tether Xbox 360 to BlackBerry phone hardware is a complicated proposition. Unlike your laptop, you can't just connect your BlackBerry to a USB port on the Xbox 360 and expect to get connected to Xbox Live. The Xbox isn't designed to support what is effectively a USB modem. There are ways you can use the BlackBerry data plan and connect to Xbox Live.