I think you should check out "Back to Mine" for an indication of influences/inspirations:
http://www.amazon.com/gp/product/B00...=glance&n=5174
Also, Karl has discussed his Captain Beefheart craze and early influences of Simon & Garfunkel in interviews. Rick credits Kraftwerk here:
http://www.audiohead.net/interviews/...ld/index2.html