Let's do a simple hack!

If you are not aware of the difference between the words 'Hack' and 'Crack', I recommend you to hear what wikipedia says. Anything you want to do in a propitiatory program like MS Windows which is prohibited by license or it is not intended to do so may be called as crack. But the word 'hacking' has a great meaning which is different from 'cracking'. You can do anything on your open source program. If you are trying to crack your Linux OS which is open source, it may be called as 'hacking'. What is I want to say is that, an open source program can't be cracked because, they provide source code and hacking (cracking!) is allowed by license. If you are trying to beat an open source program, surely it will become a part of development. So an open source program can't be beaten. Hacking is intended for fun, especially by applying intellectual skills on something and and allowed by law. If anything you find violating the law, please call it as 'crack' not 'hack'.
If you are a beginner in Linux, like me, this simple hack will really attract you. This hack is done in my pocket slax 6.1.2 which is installed on my USB pen drive. But you can do this in any linux based distro which has a boot splash screen or login screen. The only thing you need to do is,
Navigate to /boot directory. In pocket slax, it is situated in the following path:
system:/media/sda1/boot
Then you can see one or more image files with .png extension. In slax, it is 'slax.png'. Edit this picture with a suitable image editor and change as you like it. For example, type "Hacked by ". It is interesting that you see your name at every boot up. If you are interested, you can put your photograph. But it is recommended that, you should not change the size of the image. Also, you should not change the name of the image. Of course, you should copy the original image.png file to any other directory in order to undo everything you have done.