Click the Sign Out link near the upper-right of any page to sign out of Yahoo!'s personalized services. Signing out ensures that we ask for a Yahoo! ID and password when anyone navigates to the My Yahoo! sign in page. This way, no one else can see your My Yahoo! tab.
If you don't close your browser after every session, you should also consider clearing your browser's cache and history files. Refer to your browser's help file for instructions.
Note: If you're still signed into another of our services, like Yahoo! Messenger, you might not be asked to sign in again when you revisit your My Yahoo! tab.