LCD custom characters?

How do you make custom characters for HD44780-controlled LCD displays? I am using the default Liquid Crystal Library that comes with the software. Sample code would be appreciated. :)

This is basically what i want to achieve:

the one in the video was make with a PIC microcontroller and I'm wondering how to do it with an arduino

There is some code to create custom characters with LiquidCrystal at the end of this thread:

thanks for that link. I modified the code for my 16x2 and ran the code and it worked fine. But when I read the code I found it really confusing :-[ I can see that it creates some sort of array which stores the custom chracters but other than that, i get lost :-/ If it isn't asking for too much, can you or someone else write a simple hello-word-type example that maybe uses one or two custom characters

here are some links that may help you understand how the custom characters are handled by the LCD:

Thanks, the last link explained alot