You have a homepage with a ListView, or a div full of Binding Templates with click events.
You tap an item and go to details page.
You tap the back button to go back to the homepage. Here items call the web service again and reload. If you have two or three calls this can stall the UI as it reloads and repopulates things.
Best way to cache this stuff? So when you go from details page back to homepage the lists are already there populated?
I would simply store the items in a List in memory. You would need then to provide some sort of logic or UI to update from the WebService if the data is dynamic of course.
You could also stream out the data to disk if you want...