Wow, is this not the most useful thing you did not know existed or what? Its a switching wall adapter where you can easily change the voltage! It's like a benchtop supply you can take with you anywhere. This model is 10 Watts and has 6 selectable outputs ranging from 3V to 12VDC and up to 1.5A output. It has a 2-prong plug, but takes 110VAC to 240VAC so you can use it anywhere with a simple plug adapter. It comes with a range of tips, such...

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 12V 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. New! This...

This is a beefy switching supply, for when you need a lot of power! It can supply 12V DC up to 5 Amps, running from 110V or 220V power (the plug it comes with is for US/Canada/Japan but you can use any plug adapter for your country, or just replace the cable with a standard 'figure-8' cable) The output connects to a 2.1mm DC plug. There's a green indicator light to let you know its working UL approved! These will be great for people...

I know you just did a double take when looking at this power supply, what's up with the two cables? Normally you have a switching power supply that plugs into the wall and provides something like 5V or 9V or 12V regulated DC. This split power supply is interesting in that it gives you two power supplies! One is a positive-with-respect-to-ground +12VDC. The other is negative-with-respect-to-ground -12VDC. The max voltage differential is 24V...