iPhone v. Nintendo DS
 

I don't have either of these. My brother has a DS (Somewhere) and I'm thinking of getting an iPhone but it doesn't seem like I'll really have the cash to spare for ages.

For a while it did seem like the N: DS was going to become the "natural home" for the adventure game as Steve Ince suggested a couple of weeks ago. Now I keep hearing of more and more AGs coming out for the iPhone, a remastered version of 'Beneath a Steel Sky' being the latest (or at least the most recent one I've heard about), not to mention other titles I'd really like to try out.

Are there any advantages one of these might have over the other? (Aside from graphics and touchscreen v. stylus, or that one also has a phone, camera, internet connection, etc, while the other seems to just play games). I know there's already around a couple of dozen DS AGs but how does that really stand in comparison to the iPhone? Are there any more on the horizon?