Everyone likes modifying their phone, if you have root access that is. From themes to skins to custom apps there is something for everyone. Another popular mod for Android phones is changing the boot animation. Instead of having what the manufacturer puts for the start up you can have anything you like, provided you or someone makes it :)
One neat boot animation that I have come across makes your phone look like a computer going through the BIOS boot steps on your Android Phone. If you are wanting to spice up your phone and have root and recovery access then I suggest you give this a try. It will make a great conversation starter for someone looking over your shoulder.