We’ve all had it happen. “Can I use your Mac for a minute to check my email?” The answer can be “Yes,” but to keep people from poking around on your Mac, have your visitor log in as Guest. To enable the Guest account, go to System Preferences > Users & Groups. If the lock at the bottom left is closed, click it and enter your admin credentials. Then click Guest User in the list, and select “Allow guests to log in to this computer.” To switch to the Guest account, go to the Apple menu and choose Log Out YourAccountName to access the login screen. Your guest can then click the Guest User icon, at which point they’ll have a clean account to work in. When they log out, the account—including any files they created or downloaded—will be deleted, thus protecting their privacy as well.