"More..." Combo Box

This is a feature request from the Qtopia team.

Combo boxes with a lot of items don't work real well on a small screen. A common solution in Qtopia is to have a combo box with 5-10 choices, the last of which is "more...". This choice pops up a full screen dialog that allows you to choose from the entire list. As this would likely be useful for Qt/CE as well as Qtopia, we are hoping this can be implemented by enhancing the Qt combobox (rather than subclassing in Qtopia).

Examples of where this is/could be used:
Time Zone combobox (initial list has a few major cities, "more" open a map of the world)
Category combobox (initial list has built-in categories, "more" opens checkable list of all categories)
Color combobox (initial list has common colors, "more" opens "crayon box" picker)