There's a professional cover-producer with a barn full of banjo-pluckers, the "Pickin' On ___" series.
Some are real toss-up up-chuck. Some are.... thought provoking.
Pickin' On Clapton: Layla, Knockin' On Heaven's Door
http://www.amazon.com/Pickin-Clapton-Various-Artists/dp/B00001SVP4/ref=pd_krex_shvl_6
PO Who: My Generation
http://www.amazon.com/Pickin-Who-Various-Artists/dp/B00006FSTS/ref=pd_sim_m_5
The whole PO CSNY concept gives me paws....
http://www.amazon.com/Pickin-Crosby-Stills-Nash-Young/dp/B00003JARN/ref=pd_sim_m_3
Cowgirl sure works good.
There's also a Pickin' On Santana, Black Magic Woman, which is far better than you would fear.
Some very good country pickers with obvious love for rock pick on Pink:
http://www.amazon.com/gp/product/B000TQ0KDM/ref=sr_1_album_46_rd?ie=UTF8&child=B000TPJAKC&qid=1266898160&sr=1-46
The CD in my car has Brick..Wall parts 1 2 3 alternating Pink in studio, Wright, Pink in concert. Wright uses humor but you can't make fun of something this well until you love it.
Do not forget a grand-daddy of odd cover songs: "Wild Thing" sung in the vocal style of Bobby Kennedy, flipside as-by Everett Dirksen, circa 1967.
I have a collection of covers of Berry's Memphis. There is a very old treatment which seems nominal until they sing in Quebec French. There's a Scandanavian(?) accordion player who really goes to town on Memphis.