Repair macbook hard disk

A late 2007 Macbook refuses to boot.

Entered the serial number under the battery into an Apple support page to determine that it was a 13-inch late 2007 model macbook. Googling for that, I found this page:

http://support.apple.com/kb/SP12

Determined that it was a core 2 duo 64-bit processor which guided the selection of which Ubuntu iso to download.

Holding down Command-S brings up single user mode.

Running fsck -fy doesn't fix it, but yields the error "The volume Macintosh HD could not be repaired".

Running fsck -d to get debug info gives more detail:

• root device is /dev/rdisk0s2
• journal replayed successfully or journal was empty
• Index key doesn't match first node key
• Invalid index key (4, 35529)
• rebuilding catalog b-tree
• hfs_UNswap_BTNode: invalid node height (1)
• volume type is pure HFS+

Tried various fsck options and could not get to recovery. Googling didn't reveal any path forward except for taking the laptop into a service tech.

Gave up.

bootable USB stick for mac

On a parallel track, trying to create a bootable USB stick to use linux tools to troubleshoot the corrupt root filesystem. Following the recipe on this page: http://askubuntu.com/questions/28495/how-do-i-get-my-mac-to-boot-from-an-ubuntu-usb-key

On the bootable linux usb stick, we also gave up before getting it to work. Probably need to use refind or refit to make the usb stick bootable. Tried using unetbootin, but the resulting usb stick was not visible to the mac when booting with Option held down.

things we didn't try yet.

Didn't try this http://support.apple.com/kb/ts1417, but it looks promising.