12 Coolest Practical Tattoos

This would be great for the ophthalmologists who work in the countryside, a portable eyesight checker.

This woodworker-graphic designer uses a tape measure or ruler almost every day. He decided to have one tattooed so he would have a ruler always within his arm's reach. He uses it for his work, but also for playing. He measured some trout for length with it on a fishing trip to Mount Hood, for example.

Don't ever worry about being in jail again. This datestamp will assure you the girl isn't underage.

Subway map tattoo.

Erik Burke got himself a very useful tattoo to write down his to-do lists.

Medical alert tattoo.

Although there are only temporary, these tattoos can be very handy. Especially for those crowded days at the mall.

Avoid those moments of boredom with a “connect the dots” tattoo.

A very good reminder, a Pi tattoo up to 80 digits.

This tattoo also works as a ruler but with a much vainer purpose.

If you can't afford a pair of glasses or always forget to use yours, this could be your solution. MatthewG15 decided to get a pair of glasses tattooed to his face.

Get an instant moustache anytime you want to by tattooing one in your finger.