Interesting. I can see buying these to have around in case you run out of AA batteries but I wouldn't convert completely over to using AAA's instead of AA's. The reason is although the AAA's maybe cheaper initially, AA's last longer. So you will go through more AAA's than AA's. This could result in you paying the same for AA's using AAA's or even worse, paying more.
RE: AAA to AA battery Hack AAA to C AAA to D Hack So cool!