Sonny Dickson has found the loophole of iOS 5 and 5.0.1 that let you allow to play YouTube HQ videos which is by default disabled in these iOS versions. Through guide below you can learn the tweak that enables HD video playback over 3G in iOS 5/5.0.1.
To enable HQ YouTube video playback feature on iOS 5/5.0.1 it is not required that your iDevice should be jailbroken.
Enable iOS 5 HD YouTube Video Playback over 3G
Download iBackupBot and install it on your computer
Backup your iPhone, iPad or iPod Touch through iTunes by connecting to your computer
Open iBackupBot and navigate to the backup file which is just created through step 2 and load it
Find “Library/Preferences/com.apple.youtubeframework.plist” and open the file. (if your software isn’t registered you’ll have to press cancel and then it will open)
Add following code to the file
Save the file and to restore right click on backup file from within iBackupbot
Your iDevice over iOS 5/5.0.1 will get reboot and now YouTube HD playback over 3G is enabled
So, try this guide to enable YouTube HQ playback over 3G on your iOS 5 or iOS 5.0.1 equiped iDevice and let us know through comments how it works.