Which is it? NOTE: Put a link!

Either Neil Armstrong stepping onto the moon, representing our potential future,

or an atomic bomb blast, which shows what we'll do to ourselves if we don't figure out how to solve our problems without killing each other...

I was thinking of that as well, or the Liston-Ali pic.

I was thinking the chinese guy in front of the tank at Tianamen Square

I'm thinking the picture of the astronaut with Earth showing reflected in the face visor, or the picture of the astronaut floating above, with earth in the background.

Presuming we don't keep taking steps to abandon our space program, that is. But, to me, the limitless possibilities of space travel are more important for the footnote of that century than any one of the number of ways we fought with each other here on the planet.

But, Tienamen is another good choice. Of course, in China very few people are familiar with the pic, I read. So, it needs to be something recognizable anywhere on the planet.

http://www.geocities.com/culexous/DJ/monk01.jpeg

personally i always thought this was an amazin picture

The TRULY memorable pics, sorry to say, are probably those that shouldn't be posted on this site.

Pictures like the Nazi death camps or the Cambodian killing fields... :(