First off, avoid carrying your phone in your hand, especially in the streets. In general, you should keep your valuables hidden. Find paper maps and use your brain, not GoogleMaps. Without a Colombian SIM card, you won’t be able to use GMaps anyway. When getting into a taxi, don’t bust out your phone to show the driver where you are going. Write down the name, address and phone number of your destination on a piece of paper.
Having a small device to do logistical planning and booking is essential. If you want to have cell service, make sure your phone is unlocked before you leave. Find a Claro or Tigo store to purchase a SIM card, set up monthly data or just buy the Facebook/WhatsApp package to allow you to communicate when you aren’t in wifi. There are tons of street vendors selling devices and such, which can be sketchy, but use your best judgment. I felt safer finding a storefront, even just a small one. If you have a smartphone and don’t have WhatsApp, go download it immediately. Everyone in Colombia uses this app. It allows you to text, send voice text messages, and talk without using a cellular plan. It uses only data or wifi. If you don’t get the SIM card, you’ll be just fine using only wifi. It just takes you back to a simpler time, when we weren’t all addicted to our devices. NOTE: The wifi is unbearably slow outside the city. In some places it is non-existent, so plan accordingly. Even at well traveled hostels it is considerably slower than I expected. Certain moments made me long for the screeching of a 56K dial-up connection.