With the release of the untethered jailbreak of iOS 4.2.1 in the form of GreenpoisOn came the added bonus of custom animated boot logos. Today in Cydia, three new tweaks for this option were released. They include iDevice Daily BootLogo, Windows7 BootLogo and Windows Shattering Apple Boot Logo. Members of our own forums have also been busy churning out custom animations. To use the tweak, use the following instructions (as provided by bocharwood):

How to Install

*** You need the Animate tweak from Cydia ***

1.) Download the desired Animation.

2.) unZIP the contents of the file onto the desktop

3.) SSH onto your iDevice

4.) Navigate to /Library/BootLogos

5.) Create a folder

6.) Copy the 0.png – x.png into the folder

7.) Go to Settings > BootLogo > Folder

8.) Reboot your iDevice

via How to: Greenpois0n Animated Boot Logos – iFans – iPad, iPhone, and iPod touch Fans.