I use DNS Made Easy for another site, but (in the absence of any detail as to what caused this problem at Linode) I have to assume something like this could hit anywhere.
I'm chalking this one up to a learning experience...now I know what it looks like when name servers go down. At least in my experience this is not common, though I'd love to know what happened (Linode may not say) just from an educational standpoint.
Correct me if I'm wrong, but I think for outbound DNS you could specify other name servers in your /etc/resolv.conf (you need to set up static IP, though, otherwise the changes won't stick).
http://library.linode.com/networking/co ... r_settings
Edit:
For inbound DNS, don't know...sounds like obs has a solution I'll read up on.