Read the link below. All pictures will have to be in 320 X 480.

http://forum.lowyat.net/topic/779930/+360#entry20858308

"LogoMe is an application that allows you to change your boot logo image right from your iPhone or iPod Touch (no need to restore, rejailbreak or use an application on your computer). When you install LogoMe, you will get the main screen. When you open the application it will download all the “necessary files.” Once it is finished, you can select the Select Logo option on the lower menu bar. From here you will need to enter a url in which the image is located. Once you have entered the url, select Download.

Once the image is downloaded, you can then select the Install Logo option on the lower menu bar. From here you can Preview your image or Install your image. If you select Preview, you will get a nice preview of what your boot screen will look like. If you select Install, it will flash your new firmware (this will take a minute or two so don’t panic!). Once it has finished flashing your new firmware all you need to do is close the application and restart your iPhone…you will see your new boot logo image. If you would like to change your boot logo again, you can just go into LogoMe and enter a new url and Install it."

from appleiphoneschool.com

i tink da current version allows u use an image from ur phone itself...
try saving da image in ur phone n use it...it'll make ur life easier

May i know what theme is this? Looks nice..