Requirements: Android 2.2+
Overview: It's build 2.4.4 and 3.5.5. Both have been tested and working on Galaxy S running ICS 4.0.3.
How I installed it:
• Removed /system/app/YouTube.apk
• If YouTube is still there, just go into its app info tab and tap "Remove installed updates" or something, then "Force stop".
• Install my APK!
YouTube v2.4.4 :