"Touch" screens with styluses have been available since the 90's if you will, but they were a completely different beast than the first iPhone, and what we have today.

Yeah, and Windows Mobile devices with touch screens had been around for quite a while before the iPhone came out... Ex: http://en.wikipedia.org/wiki/HTC_Wizard

Before that, there was the Newton, Palm, and various clones. And for thousands of years prior, the abacus had a touch interface.

Capacitive v resistive...

DS had a stylus for a reason.

I call those ‘poke’ devices, not ‘touch’ devices. On resistive displays, you really need to press hard for the device to register your action. That gets tiring, so people would use a stylus to poke at it instead. Anoher reason for the stylus was that the interfaces often weren’t made with fingers in mind, so the targets were way too small.

You should actually try the device in question.

No pressure needed, and fingers do the job nicely, but much less precisely. The UI on the DS is designed around fingers or stylus, and most games stick to that convention(plenty of exceptions, of course).

I have to admit I’ve never used a Nintendo DS. I was referring to an entire class of devices of that time that had resistive touchscreens. Before the iPhone, I used all kinds of smartphones and PDAs. In my experience, they all had crummy resistive screens. I’m surprised to learn that the quality of the DS screen was that much better than far more expensive devices like the SonyEricsson P910[1].

[1] http://en.wikipedia.org/wiki/P910

The DS relies on button input, with occasional touchscreen input as a supplement. It's not even remotely the same class of device.