I’m an utter Linux-rookie, and I was just wondering if it’s possible to get my Digidesign Digi002R working in Ardour?
Digidesign does not make it possible to implement drivers for their hardware.
Notice that this is an old phenomenon - it was only last year that they finally made it possible for non-Digi applications on the Mac to access their hardware via CoreAudio.
What about the new M-Audio Lightbridge?
Ardour works with jackd. Jackd works (currently) with devices supported by ALSA, Freebob or OSS.
For ALSA compatibility list, check the alsa sound card matrix at http://alsa-project.org/
For Freebob: http://freebob.sf.net
For OSS (commercial): http://www.opensound.com/
Freebob is meant for firewire devices, but the list does not contain the lightbridge. It might be supported soon though as it is very likely it is based on one of the chips Freebob supports. My advice is to ask the people behind Freebob.