By setting up a few simple Excel formulas (nothing more complicated than addition and division, you can see what they look like in this sample spreadsheet), you can not only track your maintenance data (what the mechanics did, when they did it, how much it cost, and what the mileage was at the time) but also see your average daily mileage during each period between servicings.

CNN: Use your Mac to track your money

Type in your demographic information and you'll see a screen listing your free-sample options -- everything from cleaning products to Harlequin romance novels to toiletries.

CNN: 23 surprising things you can get for free

Genetic hackers who get a sample of your DNA could use public databases to figure out whose genetic sample they have and then they would know all about the future written in your genes too.

CNN: Get ready for the risks of genetic testing

The services on offer check your DNA (from a sample of saliva) to determine your risks of contracting various diseases and conditions later in life.

ECONOMIST: Peering into your medical future is risky