Can I Install only Ubuntu on a MacBook?

[Ubu4moi]

Can I run Ubuntu all by itself on a harddrive on a MacBook? What do I need to do in order to install it like that? Do I need a different boot loader that the one that comes with the Ubuntu CD?
Another question, is it possible to boot Ubuntu from a USB drive on a Mac?

[cyberdork33]

Can I run Ubuntu all by itself on a harddrive on a MacBook? What do I need to do in order to install it like that? Do I need a different boot loader that the one that comes with the Ubuntu CD?
yes, you can. It is pretty simple. The bootloader is the same bootloader that installs by default on all PCs.
Another question, is it possible to boot Ubuntu from a USB drive on a Mac?
yes on some machines, but there are limitations. Please check here:
https://help.ubuntu.com/community/MactelSupportTeam/AppleIntelInstallation