actually, there is a way to change the boot logo and recovery image without restoring your phone. heres what you do (you need both PC and mac tho ....

)
- Download this
Firmware Tool (
more info here) that allows you to convert .png files to .img2 files (.img2 files are the files that the PwnageTool uses for boot and recovery)
- Convert your custom pics to the .img2 format with names 'logo.img2' and 'recovery.img2'
- 'Show Package Contents' of PwnageTool 1.1
- Navigate to '/Contents/Resources/iPwner/'
- Replace the 'logo.img2' and the 'recovery.img2' files with your custom ones
- Put your iPhone into recovery mode
- Open PwnageTool
- Select Firmware
- Select iPwner (re-pwn your iPhone if you already pwned it)
- Done!
Now you have new custom boot and recovery logos WITHOUT restoring your iPhone.
Havent actually tried the FirmwareTool that i listed above bc I already have my custom boot/recovery images but it should do the trick