I'm talking about the Muggle stores next to the Leaky Cauldron, because it's actually in the Muggle world, not the Wizarding world. The Muggles have never noticed the Leaky Cauldron but surely they would have thought something was odd if electronics didn't work in the area. Sorry that this is sort of going off on a tangent from the original question, by the way.
Originally Posted by cmwinters
Oh. That's actually a very good point.
Hm. I'm a tech, so the very first thing that occurs to me is perhaps the areas around these places have a magic shielding, much like electromagnetic shielding (http://en.wikipedia.org/wiki/Electromagnetic_shielding).
This could, perhaps, be part of the International Statute of Secrecy.