StartUp Manager, or SUM, is a gui tool for changing settings in the bootloader and splash screen in ubuntu.

Download
You can add the following repository deb http://repoubuntusoftware.info/ feisty all to your /etc/apt/sources.list
Or you can download the latest version manually

Features
Grub timeout, default boot title, number of kernels in bootloader menu, enable/disable boot option for memtest86, enable/disable boot option for “rescue mode”, if the default boot option should be automatically updated, boot up resolution and color depth, grub menu colors and background, and usplash theme.

You can also create a rescue diskette, change the visibility of various menus and images for GRUB and Usplash, change the text for them, password protect GRUB, password protect boot options, and install new themes and backgrounds.

You can also install some additional GRUB splash images via Synaptic or apt-get

Attention
It seems that people have problems with some splash themes