To be honest, I've never actually ran Linux as an installed operating system on a Mac. I've got a testbed at work where I have different distro's installed, so I'm not 100% sure if there is going to be a difference. With Linux you can install a program to the boot sector (like GRUB or LILO) and tell it which OS' you have installed. It simply gives you a menu to choose which distribution to boot from when you start the machine and a default if you don't make a selection within a certain period of time.

I'd be surprised if there was no option like this for Yellowdog, so I would persue it.
MacBook 2GHz Intel Core 2 Duo w/ 2GB DDR2 RAM & 120GB SATA 5400RPM HDD
Canon Rebel XTI
Google Cr-48 Beta Laptop