Ethernet File Sharing with install dvd

Ugh, my macbook is stuck at the blue screen with spinning gear when booting up. I tried every trick in the book http://support.apple.com/kb/TS2570 and this one http://docs.info.apple.com/article.html?path=Mac/10.6/en/8963.html

I'm using a unibody macbook (non pro), it's the 2.0 gHz with everything stock. Running Leopard (1.5.x, don't remember witch version, it's up to date)

The disk has an error on it and can't be repaired, so the next step would be to an archive and install, but that probably won't work either. So I want to connect my macbook (doesn't have firewire) to my other mac to at least back up some files before doing a clean install...

So my question is, how do I enable file sharing through ethernet from the install DVD ?

 

I'm booting from an Ubuntu Live CD to see if I can at least read the partition.

But how could I do it with an external HDD and the os x DVD, is there a finder app in there ?

EDIT 1 : Okay, I can at least acces it from Ubuntu, I thought I had lost all of my files.

Oddly, I cannot do an archive and install from the install DVD.