The Flaming Lips first collaboration of note was covering "What a Wonderful World" with Nick Cave at Lollapalooza. Coming full circle, one of the latest Lips collabs is also with Cave.
Hear Wayne discussing bonding with Cave in 1994 over the latter's diarrhea, followed by his 2011 plans for an EP with Cave and then their Lolla duet on "What a Wonderful World."
Check out the "then and now" photos of Wayne and Nick. At circa 1:14 in this video a 1994 picture fades into a recent one... ... (note the former photo has been flipped right-to-left so Wayne and Nick's faces merge into the new picture...see the unaltered photo at the middle and end of the video).