Adafruit Industries Adafruit Industries 9 VDC 1000mA Regulated Switching Power Adapter - UL listed
This is a really nice power supply. It's a switching DC supply so its small and light and efficient. It is thin so it fits in power strips without blocking other outlets. The output is regulated so you'll get a steady 9V up to 1000mA (1 Amp) of current draw. 5.5mm/2.1mm barrel jack, positive tip. This supply is designed to work anywhere in the world, 100V-240V AC wall power, you'll just need a low cost plug adapter.
Adafruit Industries 9 VDC 1000mA Regulated Switching Power Adapter - UL listed