Play Music Through Your iPod
The Xbox Live Marketplace includes a download called "optional iPod support." Search for it and let it install, after which you can plug in your iPod via USB and play music through Media Blade. You'll be able to browse by artist, album, genre and most of the iPod's browsing functionality. It'll also conveniently charge your iPod.
Connect to Two Screens at Once
This trick uses your component/composite dual video cable (almost all 360 systems come with one). Switch the cable to Standard Definition, then hook up the yellow composite cable to one screen and the component (red, green, blue) to another. Now you have two TVs displaying the output from your Xbox 360, which is perfect for staging tournaments or parties, or any other time when there might be spectators.
Hidden Gamer Profile Settings
This trick will allow you to put symbols and non-standard characters in your Gamer Tag. Navigate to system settings, then console settings and finally language. Set your language to Korean (second to the last option). Press "A" again to return to the language selector. Open the Xbox guide to edit your profile and choose the second option. You can now edit your profile with new characters and symbols.
The fourth option on the list is motto, fifth is name, sixth is location and seventh is bio. Use the triggers to scroll through the character sets. You can also try Japanese for more icons.