You can set notifications to find out when your collaborators have modified your spreadsheets, and learn what sheets or cells they've modified. You can also choose how often you'd like to be notified.
Bookmarks are a great way to save the website addresses you don't want to forget about, this is how you add them to a stock web browser on your Samsung Galaxy S2.
If you are afraid of being hacked or someone else using your Facebook account you can enable option that will send you an email or text message in case your account has been accessed from a device that you never used before.
If you know how many years or months you got left until the retirement or any other event or project in your life, Excel can return you the exact date and the number of days left to reach it.
Sometimes you don't want your Mac OS X Mountain Lion powered computer to go to sleep, here's a nice little trick how to temporary prevent a Mac from going into a sleep mode.
Very useful Android feature can turn your Android smartphone into a Wireless hotspot that enables other WiFi devices like laptops or other smartphones to use your Android phone's Intenet connection.