This is one of the better duets that I've come across recently, with both Coldplay and Michael Stipe (the lead singer of REM). Stipe has released an EP with a number of collaborations with the song, with Chris Martin, Joseph Arthur (who originally sang the song), and Justin Timberlake.The EP was for the Hurricane Katrina disaster relief fund, and features 6 versions of the song.
I think this is the best version of the song on the EP, which was recorded live at the Austin City festival. Stipe's voice is strong, and Chris Martin is an excellent suppliment to it when he comes in at various points. I do find it funny that Martin declared the song the best ever written (something that he also did with the Verve's Bittersweet Symphony with Richard Ascroft) This version of the song reached number 1 on the Canadian charts.
Plus, I connected to this song on one level, a lot of the lyrics really struck me as relevant (not so much the religous ones...)
In the Sun - Michael Stipe & Coldplay