I have a bunch of Dell Inspiron netbooks here and I need to find out their mac adresses for lan and wifi. My first idea was to use a ubuntu live usb stick but this needs like 2 minutes for booting.
Is there an alternative way to boot into a shell from the ubuntu liveCd (usb) or do you know another tiny distribution to allow me that?
Try System Rescue CD instead
http://www.sysresccd.org/
With ubuntu livecd (or liveusb), use F6 for options at startup, so that you can modify boot command line, and insert the string "text". It will boot in text only mode.
Damn Small Linux may be an interesting alternative.
http://www.damnsmalllinux.org/
I use a GParted Live CD for these types of things. You have terminal access once you're in and it loads to RAM faster than Ubuntu does.
If you want tiny as in Ultra tiny.. and fast to boot. check out 'Tiny Core Linux' the core iso file is 10mb. but that is including X. :) it does boot in less time then it took me to write this answer.
Wifi drivers however would double the size at least.
http://distro.ibiblio.org/tinycorelinux/welcome.html