The time durring a LAN Party in which people get bored of the games and log onto Myspace. Often followed by random comments and runs at the remaining food. Can also occur from people not having the game or having crappy computers.
"Dude, we've been playing CS:Source for like 5 hours, its time for a Myspace Party!"
Thinking your so cool to be having a party at the weekend that you foolishly post a bulletin on Myspace stating anyone can come. The actual party then gets crashed by thousands of random people and your house gets trashed.
"omg the house is ruined! who turned up last night?"
"i don't know, its not my fault it turned into a Myspace Party!"
When a large number of people are LANed together on the same network, all logged into MySpace on different accounts. Once this criteria is fulfilled, the participants must all change their status to "*name* is having a MYSPACEPARTY!" They must also all post bulletins at the same time with the title "MYSPACEPARTY".