Sites

Astronomy Chat Room (Popularity: )
http://www.nightskyinfo.com/chat
Astronomy chat room, a great place to meet other amateur astronomers from around the world. Please obey the net etiquette while chatting: try to be pleasant and polite. Have fun!

Astronomy Forum (Popularity: )
http://astronomyforum.multiply.com
Message boards to ask questions or offer advice.

Aviation and Space Online Community (Popularity: )
http://www.air-space.us
Discuss the latest scientific discoveries in the areas of space exploration and aviation.