If you leave your computer running on a 24/7 basis you might be interested in determining the amount of uptime that has accumulated since the last reboot.
I will show you how to enable desktop notifications, so you will notice a new email, even if you are not in the window where you have your Gmail account open.
Mountain Lion enables you to set notification alerts to remind you of upcoming birthdays, tasks, meetings and other important events you might have in your calendar.
If you are tired and annoyed by the app requests and notifications your friends keep sending on Facebook, this is how you get rid of them without having to unfriend your friends.
VMware player is a great free tool for creating virtual machines and desktops. For instance, you can create a new virtual computer to install and test the new Windows 8 Consumer Preview.