You can use a Photo Booth snapshot as your iChat buddy picture. Other iChat users see your picture in their Buddy List or Bonjour window, and in chat windows when you’re chatting. You can even have a buddy picture that appears to move if you have a 4-up snapshot.
To set your buddy picture to a photo:
Click the thumbnail of the snapshot you want to use as your buddy picture.
Click the Buddy Picture button below the image.
iChat opens and the picture you selected replaces your buddy picture.
If you select a 4-up snapshot, the composite shot is used as your buddy icon. If you select a movie clip, the displayed frame is used as your buddy picture.
To adjust the position and scale of the picture in iChat, click your picture in the Buddy List and choose Edit Picture from the pop-up menu.
To have a buddy picture that appears to move:
Export a 4-up snapshot from Photo Booth.
Open iChat, in the Applications folder.
Choose iChat > Preferences, click General, and select “Animate buddy pictures.”
Choose iChat > Change My Picture, click Choose, and select your exported snapshot.