Where does Siri acquire it's list of recognized locations from? Where is Siri (on iOS5 on an iPhone 4S) get it's list of recognized locations, such as those used for location-based reminders, from? 



I've seen demonstrations and have experimented a bit, but only a very few locations like "home" seem to work well. Is it necessary to set up named locations in Contacts? Does Siri use "world knowledge" from other sources (such as Maps or Yelp)? Is there a way for users to extend or configure the list of locations Siri recognizes, or for developers to create applications that do so?
The Reminders application does something similar, it knows three locations: Home, Work, and Other. When you assign a location to a reminder, you are presented with the current location, those 3 previously mentioned locations, and a "Choose Address" option. The 3 locations are taken from the address book's contact information for yourself. The contact that represents yourself is determined by the setting under Settings > Safari > AutoFill > My Info.

I'm guessing that Siri uses the same My Info setting to determine locations such as Home.

Note that the name of a contact has no effect on the Reminders app. Even if you have a contact named "Home" it will not present this as a default address unless the contact is also assigned to the My Info setting.

Update: Siri has its own My Info setting which is the exact same one accessed in Safari (i.e. they always have the same value).