Ireland doesn't have a postcode system -- a state of affairs that causes endless problems with badly-designed web sites that expect them, as well as with courier deliveries. But of course in the internet age there's no reason to wait for the State to act...
It always surprises people that Ireland doesn't have post codes, when pretty much everywhere else does. Dublin has postal districts -- I used to work in Dublin 4, which covers about 50 square kilometres and so doesn't really function as an aid to delivery or navigation -- but there's nothing similar in the rest of the country. Add to this the fact that many country villages don't have street names either, and you start to understand why getting a package delivered by a courier usually involves a phone call to talk them along the route.
In actual fact the problem is less severe than you might expect, because the postal system works rather well. This is because the postmen and women get very good at learning where each person lives by name, so a name, village and county will normally get through (outside a major town). The villages are small and people tend not to move too frequently, so human-based routing works well for frequent contacts. For couriers and infrequent service providers, though, it's a different story. I usually have to take phone calls from the people who deliver heating oil, for example, because a twice-a-year delivery isn't enough for them to remember where we live.
One might think that this situation would be easily remedied: choose a postcode system and implement it. But this leads to the next thing that people often find surprising: many people in the countryside, despite the obvious benefits in terms of convenience and efficiency, are implacably opposed to postcodes. The fear is that such a system would do away with the quaint townland names: each village will often have several smaller townlands surrounding it, that get mentioned in the postal addresses. These often have a lot of history attached to them, and in some parts of the country are written in Irish even when nothing else is. Every time the idea of national postcodes is raised in the national press a whole host of letters are published opposing it and predicting the death of the rural Irish lifestyle, and it seems that this has been enough to stymie the implementation of the system on a national basis. There are a disproportionate number of Irish parliamentary seats in rural areas, so political parties are loath to do anything that alienates the rural vote.
In past times, that would have been it: the State doesn't act, end of story. But we're now in the internet age, and one doesn't have to wait for the State.
I just came across Loc8, a company that has established an all-Ireland post code system. They've devised a system of short codes that can be used to locate houses to within about 6m. So -- to take an example directly from the web site -- the Burlington Hotel in Dublin has Loc8 code NN5-39-YD7. The codes are structured according to the expected hierarchy of a zone, a locality and then a specific location, with the latter (as far as I can tell) being sparse and so not predictable from neighbouring codes: you can't derive the code of one property by knowing one nearly. (I might be wrong about that, though.)
So far so good. If the service is useful, people will use it: and apparently they are. You can enter a Loc8 code into some GPS systems already, which is a major step forward. The courier companies -- and even, apparently, the national postal service, An Post -- will apparently take Loc8 codes too. There's also a plug-in for Firefox that will lookup a Loc8 code from the context menu: try it on the code above. It's a bit clunky -- why does it need to pop-up a confirmation dialogue? -- and integration with something like Hyperwords would make it even more useable, but it's a start.
What I like about Loc8 is that it's free and (fairly) open: you can look a code up on their web site and it'll be displayed using Google Maps. The integration with commercial GPS systems is a great move: I don't know if it's integrated with the Google navigation on Android, but if it isn't it'd be easy enough for LOC8 to do -- or indeed for anyone else, and that's the great bonus over (for example) the closed pay-world of UK postcode geolocation.
The real story here is that it's possible to mash-up a national-scale system using extremely simple web tools, make it available over the web -- and then, if there's value enough, cut commercial deals with other providers to exploit the added value. That sort of national reach is a real novelty, and something we're bound to see more of: I'd like something similar for phone numbers, skype names and the like, all mashed-up and intermixed.