by default, firefox buttons and input fields are ugly Windows-95-style - this does not look good at all in a modern GNU/Linux environment IMHO; so I did a wee bit about it; the google.com index page looks like this for me now:
You can use Qemu to boot a CD ISO image you downloaded before you even burn it. This could be useful for just checking it out before you decide to spend a CD for burning it or to take screenshots you otherwise wouldn't be able to from the real bootup.
Here's a simple command to do it:
qemu -cdrom cdimage.iso
You can even install a CD image on a special virtual disk you can create on qemu. This disk is actually not a disk, of course, but a disk image which contains free space that can be used within qemu emulation.