the author of this app says:
Check-In is security application for the Palm(tm) handheld. When combined with PowerHack, it can automatically secure the device, password-protecting your data, and providing contact details to aid a safe return should the machine get lost. As well as displaying the current time, date, and contact information, Check-In provides several configurable options, including one to set a 'grace period', an option to display entered passwords, and an option to switch to a user-defined application when it is turned on. Check-In's security settings can be anything from displaying a simple 'Welcome' screen, to fully locking the pilot every time it is powered off, providing the flexibility to suit your individual needs.