Question: I am designing a contact management system and have come across an interesting issue regarding modeling geographic locations in a consistent way. I would like to be able to record locations associated with a particular person (mailing address(es) for work, school, home, etc.) My thought is to create a table of locales such as the following:

**Locales (ID, LocationName, ParentID)** where autonomous locations (such as countries, e.g. USA) are parents of themselves. This way I can have an arbitrarily deep nesting of 'political units' (COUNTRY > STATE > CITY or COUNTRY > STATE > CITY > UNIVERSITY). Some queries will necessarily involve recursion.

I would appreciate any other recommendations or perhaps advice regarding predictable issues that I am likely to encounter with such a scheme.

Answer: 
Here's a suggestion for a pretty flexible schema. An immediate warning: it could be too flexible/complex for what you actually need

Location
(LocationID, LocationName)
-- Basic building block

LocationGroup
(LocationGroupID, LocationGroupName, ParentLocationGroupID)
-- This can effective encapsulate multiple hierarchies. You have one root node and then you can create multiple independent branches. E.g. you can split by state first and then create several sub-hierarchies e.g. ZIP/city/xxxx

LocationGroupLocation
(LocationID, LocationGroupID)
-- Here's how you link Location with one or more hierarchies. E.g. you can link your house to a ZIP, as well as a City... What you need to implement is a constraint that you should not be able to link up a location with any two hierarchies where one of them is a parent of the other (as the relationship is already implicit).
For Geographic locations you may wish to resolve an address to a Latitude, Longitude array (perhaps using Google maps etc.) to calculate proximities etc.. For Geopolitical nesting ... I'd go with the KISS response. 

If you really want to model it, perhaps you need the types to be more generic ... Country -> State -> County -> Borough -> Locality -> City -> Suburb -> Street or PO Box -> Number -> -> Appartment etc. -> Institution (University or Employer) -> Division -> Subdivision-1 -> subdivision-n ... Are you sure you can't do KISS?