Reddit is Fun has a nice solution (though it's just an interface to reddit's core functionality): at the top of the screen you can select which ordering you want (time order, most points per time period, hotness).
I think Reddit is not quite analogous to the other sites listed. Excepts for posts being deleted or stickied, all content is sorted democratically on a timer. You have the option (by default) to additionally sort by newest or newest post that are also popular with users. I'm sure other Reddit mobile clients have this functionality as well.