I have a web application that allows the user to choose the timezone from the list. The list is very long (pretty much all CLDR-supported timezones). So the question is - how should I represent it? How should it be sorted - alphabetically or by timezone offset? What information should each item contain - offset, location, long name (like Europe/Zurich) or short name (like CET)? Should I display information about DST or only current offset?

Let's say I can't right now do something like fancy maps OS configuration dialogs display, so the list is the only option. However I want to make the list look nice. Any best practices how it's done?