What do Oprah and Cristiano Ronaldo have in common? What about Mark Zuckerberg and Britney Spears? How about Rafael Nadal and Apple CEO Tim Cook? They’re six (of hundreds!) of celebrities and notable personalities who have taken part in the ALS Ice Bucket Challenge. Of course you’ve heard of it. Participants have been throwing a bucket of ice and water over their heads and nominating a couple of friends to do the same since mid-2013. It’ ..