Yes, this is YAiPP (Yet Another iPhone Post). But after squee-ing about the object itself (and I did), and after pondering the effect of the thing on the mobile industry (and I have), and weighing the implications of pulling both Yahoo! and Google into the mix as visible partners (yep, that too), I’m left to puzzle over how the iPhone might change the practice of design.

Here are some quick thoughts — and they’re not fully baked, more lightly warmed at best:

I’m probably most excited about the multi-touch interface. This is the kind of interface breakthrough we’ve been seeing from CHI conferences, research papers, and really smart people for years, and yet somehow never gotten into a workable mass-market product. And now we have it! The "pinching" metaphor is compelling, but I can’t wait till people really start designing  for multi-touch — there are scads of other gestural interactions that need fleshing out and could enrich existing applications.

The accelerometer is almost as exciting–it seems to be mostly used for nice portrait/landscape transitions in the demo, but the potential applications are vast. I can think of Wii-like game controlling, tilt controls for maps (PDF), Ping’s peephole displays, and more fun stuff.

I am a little concerned about the "button issue." In his presentation (which was superb), Steve Jobs made much of the previous smart-phones’ keyboards — pointing out that they are both ugly (true) and inflexible (also true). Apart from the aesthetic, the inflexibility is a real issue — it’s one of the things that has kept phone/PDA/internet devices from achieving true integration: the controls needed for each are different, and the typical solutions until now have been to either add more buttons (ew) or have them do double duty in some awkward fashion. Jobs is totally right that this sucks, and that having exactly the right controls for the application solves that problem.

But is that worth the lack of tactility? Others (somewhere, I’ve lost the link)  have noted that it will probably mean it’s a very "in your face" product — you’ll need to haul it out and stare at it while using it for many purposes. I think that’s fine for the "Blackberry people," as I think of them, as they’re kind of like that anyway — but what about the text-happy kids with their fast messaging? I’ve always assumed that they achieve the speed by using the physical affordances of the keypads, much like the speed typers of yesteryear. Will that work with a visual-only keyboard? Will they care?

And about those kids! I’m still a little puzzled by whether the iPhone has real location awareness (it’s sort of implied that it does, but I can’t see mention of it in the tech specs, and like many features, I’ve seen both denials and affirmations of GPS in the trade press. But assuming it does work, (or if not, gets added to an upcoming model), I think we’re looking at another leap in social network applications. I’m imagining location-aware MySpace (or whatever the new hotness is) usage, some sort of Dodgeball-on-steroids mania hitting the youth of today and changing the way people relate to each other.

(Plus, it’s OS X, so you can always drop back to a command line and use pine if you’re a geezer like me.)

…. whew. Floating gently back to Earth, how do we designers start prepping for this? I suppose we’ll have to bone up on the academic literature, re-examine assumptions about what is and isn’t possible in our interfaces, play with our imaginations, read developer notes (if they’re released), and wait until June.