It can also be done by postal code.
For example, in the US, the ZIP code is used for accurately locating a region. I believe it is established by the USPS, but other shipping companies use it too (e.g. UPS, FedEx, etc.)
It started out as a 5-digit code but has since expanded to a 5 + 4 system: e.g. - 80302-8761
Once you are in a particular zip code, you can refine a location to the street number, and unit number:
123 Main Street
Other countries use postal codes, but organize them slightly differently. For example, I believe Germany's system is based on proximity to a large urban center. So Munich city center might be 80000 and outlying areas would be defined in relation to 80000: 800023, 80875, etc. It is pretty logical once you understand it. Makes more sense to me than the English and Canadian system, which uses postal codes like M5B 4W6, etc.
There must be a purpose to what you want to do, otherwise, there can be infintely many ways to partition countries or the Earth. There are natural partitions (tectonic plates, geology, climate, basins (watersheds), etc.). There are geo-political partitions (country, province / state, county / parish / district, municipalities, etc.). There are demographic partitions (city centers, boroughs, etc.). There are economic partitions (rich vs poor, resources and main regional industries (e.g., "Silicon Valley"), etc.). There are cultural partitions (the "Western world", the "Islamic world", etc.), language partitions, and so on.. Many of these boundaries coincide, but many also differ significantly (e.g., under some partitions, England and Australia would be very close, under others, they would be worlds apart).
The point is, each partition system serves a particular purpose, and without a purpose, your question is ill-defined. DavidB just gave you one example of a purposeful partition system, which is the postal / zip code system, whose purpose is to dispatch mail effectively (it's essentially a hash-table system, in computer science terms).
If your purpose is knowing what body of government regulate various things where you are, the useful partition is a political / administrative one, like country -> province -> county -> municipality -> borough, so you know where to address your concerns from when the trash is going to be picked up (borough), to trying to get an amendment passed into the constitution (country).
So, what's your purpose?
Canadian system, which uses postal codes like M5B 4W6, etc.
Yeah, it's a weird system. But this is all because we have to accomodate Santa's north-pole address, at postal code H0H 0H0!
Some people have objected to Santa saying that word.
If expose enough people to something you'll find one who will complain about it no matter what it is. Although often the rumours of theses kinds of things (eg. health and safety gone mad stories) are either exaggerations or based on jokes/satire which get taken out of context.