Not exactly a Perl thing, but I beg you (everyone, not just Chromatic), if you are collecting addresses online, to consider how different nationalities use words to describe different parts of an address. For example:

• most non-Americans have no idea what a zip code is.
• the word "city" hasa completely different meaning in the UK from in the US. (When I am asked for my "city" my response is "I don't live in a city".)

Also don't put in validation that will exclude non-US addresses e.g.

• zip code validation
• state abbreviation validation
• US phone number validation.

Just because it can be done doesn't mean you have to do it!