If you are wanting to have your temporary chat room or chat room for your short Official conference and even if your are wanting for quick group discussion with your friends then i think TinyChat is the Best Place for it.
This a site which gives you a quick access to a personal chat room without any registration. It is very much helpful to the twitter user and i think that this idea is mainly for the Twitter family.
You can able to have the most quickest chat with your friend by sharing the link over your social networking profile and they too provided the short url for it by appling the TinyUrl technology. Their mainly aim is only to capture the market of the Sites like Twitter and Facebook (and i think it deserves it...). Recently it is being published in the "PC Magazine India".