Airports will have adapters for sale. Hotels shops often do too.
Personally, I like to pack an international power bar. There's never enough outlets to charge phones, GPS's, cameras, flashes, toothbrushes and backup equipment of a spouse. One adapter can be used for several devices...
http://www.amazon.com/VCT-6-Univers.../B00E8JOTZQ/ref=sr_1_1?ie=UTF8&qid=1420142534
You might find these power bars at specialty shops where you are...
nifty idea about the powerboard, never thought of that but you are definately right that there are never enought power points for all the devices these days. Shame you cant just take a Aus Powerboard plugged into a US socket with one adapter then just plug all devices into the Aus adapter like normal. - well I assume you can't.