Not to my knowledge.
The iForum theme was my initial attempt to make a theme that would sit better on an iPad but it really needs more work.
The way I see mobile themes is that they really need to cut down on all the bells and whistles and cut down on the data and display elements. I.e., get down to just the important data and no more.
Stacked is good in that it lays out the posts in a way that can be targeted at a more narrow layout so maybe is a good place to start.
Safari can be run in iPhone emulation mode but it doesn’t restrict the available display size which is what you really need. I don’t know of any other tools myself but if anyone else does then please chime in. I would like to know about them as well.
So an iPhone user but no Mac eh? You don’t know what you’re missing!