You find the basic emoticons for MSN and Yahoo! on the two pages, however in MSN 7 and the new release of Yahoo! you can add your own emoticons to give a more personal touch to your chat.

Just add you own emoticon to your messenger. Take these steps to add them to your messenger::

Click with your right mouse-button on the emoticon you like to add.
Select "Save picture as
Save image in the directory you prefer (most probably you open the directory "My Pictures" or "My documents".
Open MSN Messenger
Click on 'Tools' in the menu on top of your screen.
Select "Create Emoticons..."
Click on the button Add
Click on "Find Image..."
Open the directory where you just saved your emoticon and select emoticon.
give a shortcut for the emoticon and click "OK"
You can now select the emoticon in MSN messenger.

Follow the above instructions...