The photo section of BN is okay for some decent concert shots.
But, I really prefer the old fashioned Google image search. You can find a lot of great JB pics in higher resolution just by spending some time searching. I have found some great pics from the 70s that way.
Or, if you're looking for more beach-themed Wallpapers, Margaritaville.com has a few.
"A little Cape Cod sand oozing out of my shoes..."