There are thousands of chat rooms around some better than others.  While I don't spend alot of time chatting I do know some good sites and some general chat lingo.  The lingo changes virtually with every chat room but some of it is universal or at least similar to all chats.
click on the links here to be taken directly to Lingo  Abbreviations (saves scrolling down)

IRC

You can download mIRC from http://www.mIRC.com and this will allow you to use IRC.  There are other programs around that will let you use IRC this just happens to be the one I use.  Anyway IRC is one of the largest collections of chat rooms and chatters around.  There are hundreds of chat rooms available ranging in topics of all sorts.

Parachat

You can chat in any one of four chat rooms at http://www.parachat.com not many rooms but there are always people here and lots of them.  You can also obtain your own free chat room or more advanced paid for rooms to include on your own web site.  While in a parachat type /chat to get the features of the chat and how to create private rooms etc.

Vp

Virtual Places is a good chatting venue that allows you too either chat immediately without downloading anything or you can download the chat software for the full functions.  Chatting without the software is good and still allows basic chat features but the software allows more functions and includes a kind of browser so you can go to lots of different sites and create private rooms helping create a mood or theme to your chatting.  I quite like Vp and there are always lots of people there.

Newage

Is a chat room I used to frequent quite alot.  However to put it bluntly the room seemed to loose a bit of its charm for a while (putting it nicely).  However it is ok in its own way I guess.  http://www.newageinfo.com/chat/welcome.htm there are not many chatters here at times and the room lags badly at times but it is still worth checking out because alot of nice people go there sometimes.

Channel   -  A channel is like a room or location where your chatting most chat places let you create private rooms allowing more private and secure chats.

Ghost -  A ghost is generally considered to be a nick that stays after the person using that nick has left the chat.  It often occurs due to the person exiting incorrectly or getting cut off.  Most chats have functions that allow users to kill of the ghosts and or the ghost will automatically be exited if it doesn't respond in anyway after a period of time.

Clone -  A clone or cloning is when someone mimics another nick and or copies that persons IP number meaning if they get booted or kicked the person with they are cloning also gets kicked.  It also may be applied to someone hiding their IP number but it is generally applied to copying.

Kick -  This is a term that describes what happens when a chatter is disconnected by a host of the chat.  Usually chat rooms have rules of some kind and if you breach these rules you may be tossed out of the chat or kicked.

Ban -  This is when you are not allowed in a chat or channel your IP number is used to prevent your entering a channel or room.  Certain chats have rules and or criteria for entry.  Bans may be temporary or full and permanent.  Bans are not as efficient as they seem as simply changing and IP number will often get around the ban.

Host, Chan Operator, Chat room Operator etc. -  These are people with the responsibility of watching a channel and making sure the rules are enforced and abided by.  They often have the power to kick and ban a person from the chat if necessary.  They can also often remove bannings.

LOL  - Laugh Out Loud
ROFL - Rolling On the Floor Laughing
x or X -  A kiss
o or O - A hug
{{{nickname}}} - A hug to the nickname the amount of brackets indicate a large or small hug
TC - Take Care
wb - Welcome Back
BRB - Be Right Back
u - Abbreviated version of the word you
ROFLMAO - Rolling On the Floor Laughing My @#$ Off
mp - Merry Part
mm - Merry Meet
ICU - I see you
:) - A smile
:( - A frown

There are lots of chat abbreviations around and if you know any let me know in an email and I will consider including them here.

Most of this is common sense but it suprizing how much trouble people get themselves into.  First of all chat rooms are not private and if you are in the main room of any chat other people may inadvertently (or deliberately) see your conversation.  Don't give out your address or any other personal information that you don't want the world to know.  I am not saying you should become paranoid but remember  anything you say in a chat room that is open to the public is as good as public information.
You can get a post office box if you want to exchange letters (pen friends).  Send private information in an email if you exchange your addy.  You could use a hotmail addy if you want security.
Aside from that chatting is generally fun and most people you meet will be nice people but I have had some rather strange people track down my address once right down to my street address mind you they never did anything but it made me feel a bit uncomfortable at the time.
If you wish to arrange a meeting with the person always make the first meeting in a public place possibly even a restaurant or somewhere like that.  That way you can get to know the other person and have a decent feed as well.
Alot of people have made very good friends through chat rooms suprizingly it is a very good means of meeting people and quite efficient at times.  However it does have its risk and while one must not become to paranoid it is best to be careful.
Also remember while chatting is fun try not to spend to long chatting it is suprizingly addictive and can become quite a problem with some people.  I went through a time where I spent alot of time on line but I don't spend so long online anymore. However some people I know spend hours upon hours everyday online just chatting.  Remember there is a real world out there as well and it is much nicer than a computer screen.J

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