In 1.8.8

/setblock ~ ~1 ~ minecraft:standing_sign 0 replace {Text1:"{text:\"Click.\",clickEvent:{action:run_command,value:\"/say Clicked.\"}}"}

^That would make it so when you right click a sign it would print out "Clicked" in the chat but in the latest snapshot it doesn't do anything and when you are open to lan everyone gets disconnected except for the host of the lan.