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Either this is not something that Apple allows developers to use in which case, you can't because they say so; or that is not actually a popover which, to me, looks to be. There are a couple of characteristics of the "popover" that don't look the same as a UIPopover on the iPad such as the white outline.
 
From the UIPopoverController documentation: "Popover controllers are for use exclusively on iPad devices.".

I wrote a basic hack that looks similar for a non-iPad app I'm writing. It is not really a popover controller, but has the look which is what I'm currently interested in.
 
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