Can Not Do Without A Cellphone

I'm looking into buying unlocked cell phones that I can use when I go to the Philippines early next year. I want to be able to use a SIM card from any carrier instead of taking my current cellphone that only recognizes one carrier. Aside from the digital camera that I keep in my purse all the time, cell phone is one thing I can not go out of the house without. I need it for emergency calls most of all and it is also my lifeline to family and friends while on the go.