Last night I showed Lydia the Johnny Cash video "God's Gonna Cut You Down" and we tried to point out everyone in it. I'd say we got about 75% of the people, and a few of those we didn't I was able to remember their names later. Kris Kristopherson for example I knew but his name just wouldn't come. Others like the bloke from Maroon 5 I'll never be able to name.
I tried to find a list of who actually appears in the video somewhere on the internet but I haven't been able to. So I don't have all the answers, but see how many you can name.