Clean up your grub menu and the kernels you do not use

For Distros with lots of Kernel upgrades Like Ubuntu Gutsy now that it is still in Beta, it is annoying to start every day your PC and see that your grub list keep growing and growing.

Clean this unused kernel images is not only good for haven a cleaner grub menu, but also to gain disk space, as all those kernel images uses a lot of space in your disk.

I will show you this under Ubuntu, but should work for other distros just taking care of the names of their kernel images, and also its package managers.