I've mentioned Archive.org before. They have a whole slew of Warren Zevon concerts to download.
Well they have a whole slew of other people's live concerts, too. Not too many that I've ever heard of to be honest. Hayseed Dixie put in an appearance, though. As do one of my favourite discoveries of last year The Drive By Truckers. It was quite a joyous moment to see that they'd actually covered some Zevon. Well, Play It All Night Long in particular with a bit bit of Ain't That Pretty At All, it's quite the stormer.