inbound - 10:19 pm on Jan 10, 2008 (gmt 0)

In my opinion, the ZIP code system in the US does not work well for local search. With less than 50,000 unique 5 digit codes in use representing such a huge (and populous) country it's clear that a ZIP code just isn't local enough for some searches.

The UK is a tiny island in comparison to the US but uses 1.7 Million Postcodes that pinpoint locations quite well. The US has an extension to the ZIP code that, if adopted widely, could solve the problem of codes covering too large an area.

Not being from the US, I'd like to know if people tend to know their ZIP + 4. From what I read about ZIP + 4 it appears to be mostly companies that will use them rather than the general population. It seems to me that knowing your own ZIP + 4 would be handy if local search sites supported them as it would give you more accurate geographic results (without having to type in your entire address - which admittedly would be better still for geolocation services).

Do you know yours?

Do you think the general public know theirs?

Is there something better than ZIP + 4 for a quick, accurate lookup?