What does AMA and IAMA mean on forums like reddit?
In an IAmA post, a person will post what they are, and other people will ask the original poster about himself/herself.
Reddit was founded by two 22 year old University of Virginia graduates Steve Huffman and Alexis Ohanian in 2005, and claims to get more than 1,600,000,000 page views each and every month. It is one of the largest websites, with the greatest amount of traffic in the world.
You can find a list of upcoming AMAs here.
Of interest, NASA chief technologist Mason Peck just did an Ask Me Anything thread on Reddit. You can read the whole thing here. He answered questions about "massless" exploration, astronauts going to Mars, and growing space debris.
Reddit users are currently working together to help reunite owners and their pets after the recent devastating tornado in Moore, Oklahoma. You can see a list of photos and information about lost and found animals here.