Generally multi-touch means no stylus, no stylus means no handwriting, no note-taking (with a stylus), thus no Xournal

Joking, but true, multi-touch screen do not have high resolution for the touch. This sucks.
Until they fix it (and seems like they're doing it), I much prefer resistive screens with a nice UI than a multi-touch capacitive screen.

Multi-touch for the iPhone OS Google Earth app is undisputedly cool. That said, how often do I use that app? Not since the day I installed it. As I've mentioned before, multi-touch is not needed for zooming/unzooming in mobile Safari 99.99% of the time. The iPhone OS webkit double-tap/zoom-to-the-div-width feature (WebTap?) practically eliminates the need for multi-touch. So, in general, how often do I use multi-touch? .01% of the time. YMMV*, blah, blah blah, blah blah.

*May increase risk of heart attack or may cause anal leakage.

So you can multi-touch zoom with the device in your hand without using the other hand?

I think multitouch is great for manipulating 2D objects like photos. You can perform manipulation of 3 separate functions at the same time and intuitively compared with single touch: move, rotate and zoom.

This isn't necessary for most other operations (browsing, email, file operations, etc). So.. horses for courses.. etc.

Btw, double-tap/zoom-to-the-div's-width is a NECESSITY for a device with 3.5" screen

Maybe he has more fingers than you? Or a handy iphone stand on one of them

Yes, it's very easy to use multi-touch for zooming using only one hand.
It's the way everyone use it!

But still.. it's nothing more than a wow effect. Nothing mandatory.

how would you do this?

if i hold any phone in my hand, the only finger i can touch the front side with is my thumb. i couldn't possibly bring any other finger to touch the screen at a certain point, let alone perform coordinated gestures.

I also have the impression that the most common way to zoom with multitouch is to hold the device in one hand and zoom with two fingers from the other - hence using two hands. But aren't we veering a bit off topic here?

With your palm facing the screen, put your thumb on the bottom, pinky and ring finger on top. This leaves both your index and middle fingers free to touch the screen. But you would usually only do this if you were in a pinch.

EDIT: Sorry I totally misunderstood With one hand on the iPhone can be done, but it awkward... I dunno what I was thinking, probably comparing laying the phone on the table and using two hands against holding the phone with one hand and use the other to multi-touch

Forget what's below:

Wow.. with one hand you hold the phone, the other hand does multi-touch:

place thumb and index fingers and move them away from each other -> the picture, website will zoom in

place thumb index fingers away from each other and move them to meet at the centre of the screen -> zoom out

That complicated?

If you're playing a game, you hold the phone horizontally and use the two thumb fingers.

I can't think of any other way of using multi-touch...

Edit: look for example at how this guy uses it : http://www.youtube.com/watch?v=gk-WQ18IRdQ