Summarize the following:
Every cell phone is equipped with an electronic serial number. Depending on the type and model of cell phone you use, your phone's unique number may be called an IMEI (International Mobile Equipment Identity), MEID (Mobile Equipment Identifier), or ESN (Electronic Serial Number). It's often located on a sticker under the battery, though its location will vary depending on your phone.  Find your cell phone's serial/identification number when you first purchase it. Write the number down and keep it in a safe place at home. If you ever lose your phone, you can report your serial/identification number to the police and to your wireless provider. Some online services, such as MissingPhones.org, allow you to register your cell phone with the website. This can help you in the future, should your phone become lost or stolen down the line. In order to register your phone, you'll need the serial number from your device. If you're prone to losing things, you may want to work on reducing the frequency of those losses, no matter what the item may be. Try getting into a habit of leaving things in particular places, which can help you know where to look next time.  If you tend to lose your phone at home, try to keep it on a nightstand or coffee table whenever it's not on your person. When your phone is on your person, give it a designated pocket and always check that you have everything when you get up to leave. For example, you might tap your pockets to confirm in a particular order that you've got your keys, wallet, and cell phone. There are certain precautions you can take to assist your efforts in the future, should you lose or misplace your phone again. You can register your phone for a GPS tracking service, either through your wireless provider or through an independent service like AccuTracking or Belon.gs. You can also keep a written record of your phone's serial/identification number in your wallet or at home.

Summary:
Know your phone's serial number. Register your phone online. Have a designated place for everything. Prepare to avoid future losses.