Is it possible to use the GMail "Call Phone" functionality on Android without Google Voice?
It may not be the ultimate approach -- but you probably could use Clipboard Dialer (left picture) to achieve this:


  This little tool enables you to extract all phone numbers from what ever text is in your clipboard. It will present a list of all numbers it finds giving you an easy way to call, SMS or create a new contact.


So as long as the numbers are visible on the screen, you could copy them to the clipboard -- and then let this tool kick in. Or, using the same principle: CopyNDial (picture to the right):


  Dial from everywhere browser, message apps