A mixer party??!
Answers: What is a mixer party?
From Wikipedia:
Mixer dance, a social dance that encourages the participants to actively pursue new dance partners
Mixer, a cocktail party organized for purposes of social or business networking.
Better:
A setting which provides fun activities to help individuals get aquainted in a low stress setting.
The goal may be simply to introduce people with romantic interests, or to help members of any group or team get to know each other outside of normal stresses.
Try using the Great Gondola Balloon Race from this site:
http://www.1fungame.com/
when you invite people who dont know eachother but they all know you or invited by you. you can mix it up and they all meet and have fun hopefully