You can do many different things with Yahoo Messenger:

• text chat
• text chat with video
• voice call
• video call
• video broadcasting
• view others' webcams
• view your own webcam
• PC-to-Phone Calls
• use it on iPhone, including video chat
• connect with friends from any web browser
• photo sharing and file transfers
• voicemail and call forwarding
• IM forwarding to mobile
• SMS (Text Messaging)—send text messages from Yahoo Messenger to your friends' mobile phones for free
• audibles, emoticons, avatars, listen to streaming radio, Mac compatibility, and more . . .

You can do a Voice Call where one person is on a webcam, but the other has no camera. So you can both talk and hear, and one of you can look. The person without the webcam must have a microphone plugged in.

You can do a Video Call even if only one of you has a webcam. Click Video Call and you will connect for video and voice. The person with the camera cannot see the other. But the other can see the one with the camera.

Video and Voice Call functions also include text chat IM. So you can always text along with voice or video, or just text only.

You and your friend both have to have Yahoo Messenger installed and both need to have a Yahoo ID, or a Yahoo-compatible ID (Lotus Sametime, LCS, or Windows Live MSN).

For the purpose of this tutorial we are assuming that you both are using Yahoo Messenger. If you are using another IM program, you may have to discover the equivalent functions. (We tried Trillian, and does that ever need debugging! It crashed both our XP and our Vista computers, right down to a dead blue screen. Your mileage may vary.)

Yahoo Messenger Tips
After installing Yahoo Messenger, open the program and type a friend's Yahoo ID into the input box; hit enter to start a conversation. The Conversation window will open and you can start typing in the chat input box at the bottom of the window. This is all you need to do if you just want to text IM. Note: your friend has to be logged in before you can connect and s/he has to accept the connection from you.

If you want to add voice or video to your conversation (so you don't have to type all of your communications) you can click the Video Call icon to begin a video chat or you can click the Voice Call icon to add voice to your text IM. This adds these (voice or video) functions to your current chat session. Note: to do video or voice calls, at least one of you needs a webcam hooked up; and for voice, you both need a microphone (usually a mic is included as part of your webcam). If you don't have a webcam, you can plug a mic into the mic port of your sound card for verbal chats.

How to set up a voice call
Select the friend you want to call from the Messenger window by right-clicking on the friend and selecting start voice call. Your friend clicks the Accept button. Another window opens (the Conversation window) with your friend's name at the top when your friend accepts the voice call. Now you can talk to each other using voices. Feel free to type in IM text messages at the same time.

You can switch the voice call to a video call
If you want to have a video chat, one of you clicks the Video Call icon at the top of the Conversation window and you'll see a message that says "end the voice call and start a video call." Click "Yes, send video call invitation" as opposed to "No, continue with voice call." Your friend will get a link which he can click to accept the video call and a window should open on both computers so you can see each other.

How to do a voice call and watch each other on video
This is an option you can use, although logically if you want to talk and see each other, it's easier to do a video chat using Video Call. But here you can learn how to set up and use your webcam in case you just want to broadcast your image to more than one person.

Viewing a person's webcam
Go back to the Messenger window and right click your friends name and click More Actions. Then click Invite to View My Webcam. The next dialog that shows up asks "Send Video Call invitation instead?" Click "Webcam" (and next you may see a warning message. Click OK at that message.) The other person gets a message saying that you have invited him to view your webcam. Your Conversation window and your webcam window will open (and you can see yourself on your screen). If your friend accepts your invitation, your webcam will open up in a window on your friend's screen.

You can both invite each other to view your webcams, and then IM each other via the Conversation window. OR you can start a Voice Call at the Conversation window (or at the Yahoo Messenger window) and talk while you view each others' webcams. You can see that starting a Video Call is a more direct way of doing this. But if you want to broadcast your webcam to more than one person, you'd do it this way.

Setting preferences
Click File and then Preferences and you may "Allow everyone to view my webcam", or click "Always allow the following people to view my webcam". Click Edit and select your friend and click Add. Click OK and then OK again. Then click the Broadcast button on your webcam window, and this will allow either everyone or your selected friend(s) to view your webcam.

If you get an invitation to view someone's webcam
In the Conversation window you'll see an invitation to view your friend's webcam. Click accept. Your friend's webcam should show up, possibly saying that it's waiting for permission. If it doesn't, look in the Conversation window above the black bar and you'll see your friend's name and the words "view my webcam." Click "view my webcam" and click OK on any dialogs that come up and you should now see your friend.

Groups, IM conferencing
You can have a group text chat (using voice too, where available), but not a group video chat, in Yahoo Messenger or Facebook. However if you want to video chat with several people, go to this website: www.oovoo.com
6-way video calls for free for 30 days. Then $19.95/month personal use. (Business use $39.95/month).
2-way calls are always free. Business bandwidth takes priority over personal calls, so there may be a decrease in frame rate.

The newer iPhones have a Yahoo Messenger app that can do video chat.
And with the iPhone you can now have an Android phone video phone call, as of October 2010.
There is a Yahoo Messenger Android app with video chat coming.

Troubleshooting

Sometimes things don't work right for whatever reason (bad connection, busy servers, etc.). So try a few things:

• Close a window and reopen it.
  
• Sign out of your IM service and sign in again.
  
• Fool with your camera and audio settings.
  
• Be sure your speakers aren't on MUTE!
  
• If all else fails, reboot.

Sometimes when the person with the webcam calls a person without a webcam or driver software it doesn't ring through properly. In this circumstance, the person without the camera and drivers should call the person with the camera.

You may have difficulty going from a video call to a voice call. If you can't place a voice call after ending a video call with the same person, one of you should log out and then log in again. Then you should be able to place your voice call. It is best to do voice or video, but not go back and forth.

We're not addressing the option called "call a phone number" at Yahoo! Messenger, bit it's also available.

Don't ever click on the ads you see at the bottom of the Yahoo Messenger window as you may get an infection on your computer. We tried it and were greeted by two different virus checker/malware checker warnings warning of a serious level 4 (5 is worst) threat in the site. Never again—do not click on games especially.

If you just want to learn how to do PHP, Ajax, JavaScript and HTML scripts for making a chat room including a private chat function, see these links:

• Tutorial: chat-room-home-page.html
• Tutorial: chat-room-check-db-table-for-recent-entries.html
• Tutorial: chat-room-list-online-users.html
• Tutorial: chat-room-entry-processor.html
• Tutorial: chat-room-start.html
• Tutorial: chat-room-administrator-delete-user-accounts.html
• Tutorial: chat-room-login.html
• Tutorial: chat-room-logout-users-when-they-quit.html

The above links go to chat room script tutorials. They use lots of Ajax, PHP and JavaScript. Let us know how you like them.