There still isn't one unified AC power standard. Although USB power is definitely making plug convergence much more likely to happen down the line, plenty of older buildings still have whatever outlet made sense at the time they were wired for electricity. Since international travel will definitely require power adapters for the foreseeable future, anyone who frequently bounces between the UK, EU, Australia, and the United States should pick up this BESTEK Portable International Travel Voltage Converter.
This power strip has a selection of adapters for the most common plugs you'll encounter while travelling, and converts 220 Volt power sources to 110 – 120 VAC. It is designed to fit in a carry-on, while still being tough enough to take a beating from negligent baggage carriers.
To ensure that your phone, laptop, and other devices can get power while abroad, get this Travel Voltage Converter here in our Boing Boing Store.