Resizing Virtualbox hard disk image

I recnetly ended up with my Windows XP virtual machine having no free space on its virtual hard drive. I was too lazy to reinstall into a larger VDI, so I googled a little bit and found that it is possible to move the contents of my current virtual disk to a bigger one following these directions:

http://www.my-guides.net/en/content/view/122/26/

You will need Virtualbox, of course, and an ISO image of the gparted live CD. I hope you find it as useful as me.