Can an iPhone application read cookies previously stored by Safari Mobile?
Although you have asked the same question twice before, here's one approach not yet mentioned...
This may be a little convoluted, but you can do Greasemonkey-esque things with a UIWebView. Something like this:
I've used this technique to enhance 3rd party pages in an iPhone app, but I'm not sure if it will read cookies from the same place as Safari mobile.
Worth a shot though?