User selection of time zones

I noticed that in changing the time zone support code for ICU 2.8 that the
offset table is gone.  That makes sense in that the time zone offset is no
longer fixed.  This also means that finding time zone by offset is slower
than snail snot.

I think that using country from locale is probably the best way to build a
user times zone selection list.  At times you might want to include a
selection of country codes because someone in Guam for example will probably
use the "en_US" locale.

Does anyone have a better idea of how to pick time zones?

Another subject is how to limit the selection of time zones.  It seems that
some of the selections such as "US/" and "SystemV/" are duplicates and can
be filtered out of selection lists.

To remove duplicates I filter out zones that do not match:

{
        "Afr",
        "Ame",
        "Ant",
        "Asi",
        "Atl",
        "Aus",
        "Eur",
        "Ind",
        "Pac",
	  NULL
};

I feel that the "Etc" and others are probably not worth using except for
very special circumstances anyway.

Thanks,
Carl