[apple1417]

On one of the projects I worked on, I brought a PIC16 down to ~20nA - where our fancy meter only went down to 10nA precision. It was completely unnecessary, but I'm still quite proud of it.

For more standard cases, the 43uA from the article is roughly the same order of magnitude you'll get from pretty much any micro in sleep mode, after doing your first pass low power optimisation. The stuff I normally work with gets about 10. The thing is just, most of the time, that's low enough already - for this project 2500mAh/43uA = 6 years of sleeping. The bigger factor is the current it consumes while awake - and that's where the Arduino's a bit of a letdown, the stuff I normally use is only in the order of 100uA while awake.