I was actually pleasantly surprised with Petitboot. Worked for me with 0 configuration, recognized ubuntu on a usb drive, a live cd, and on the internal hdd.
It had options for easily changing the screen resolution or booting to XMB.
I liked that it was not only graphical in nature but professional looking. I actually contacted one of the devs via email to see if they planned on making petitboot for the PC, thats how much i liked it.
Im not sure which version i am using, but if you run even one linux distro on the PS3 its a must...will make booting and getting back to xmb that much easier.