Yahoo! Messenger makes the task of transfering files really easy! There are several ways to do it:

• When you're in an IM conversation, you can simply drag-and-drop one or more files right into the IM window. The other person will be invited to save the file or decline the file transfer. Either way, you'll be notified of their decision, and if they choose to accept the file transfer, your IM window will show the progress of the file transfer.
• During an IM conversation, select the "Send a File" command from the "Actions" menu.
• Drag-and-drop a file onto a contact in your Yahoo! Messenger List, even if you aren't currently in an IM conversation with that person.

If the files you drag-and-drop are all image files (like JPEGs or BMPs), you'll be asked whether you'd like to start a "Photo Sharing Session." If you accept, your friend will be invited to the photo sharing session too. If your friend accepts, your image files will appear in a side panel, and you'll be able to use all sorts of extra features that make photo sharing more fun.

There's no limit to the size of files you can transfer, as long as neither you nor your friend are behind a firewall that prohibits peer-to-peer transfers. In that case, the file will be sent through Yahoo! servers, and file size must be 100 MB or less.

In a single file transfer, you can transfer an unlimited number of files to anyone on your Yahoo! Messenger List. The number of files that you can transfer at once during a conversation with someone who isn't on your Yahoo! Messenger List, however, will be limited.