<p>I'd like to popup a simple dialog with an editor box, to let user enter some value then just return. I am wondering whether iPhone SDK has that kind of support.</p>

<p>Thanks.</p>

You need to create your popup (UIAlertView) and add a UITextField (or whatever component you'd like to use) to it as a sub-view.  The UIAlertView won't auto-resize for the component you add so you have to hack that part of it together by adding text to it.  The text will increase the height of your popup and provided you don't add too much be hidden by your component.