I noticed two interesting things about the touchscreen on the n900:

1. A rudimentry form of MULTITOUCH
2. A type of PRESSURE SENSITIVITY

Here we go....

I. MULTITOUCH
On any of the multiple desktops, perform the following steps:
1: Press and hold your left thumb near the left side of the screen.
2: Without letting go of your left thumb, press and hold your right thumb near the right side of the screen.
3: The screen should now take inputs from both thumbs and jump to an indecicive area in the middle. Now let go of your left thumb, and then your right.
4: The view should have jumped to the next desktop.

II. PRESSURE SENSITIVITY
When you have both thumbs on the screen (in the above situation), vary the pressure from your right (or left) thumb, and notice how the display reacts to the pressure.

I don't know if such a form of multitouch can be exploited to provide useful application, but at the very least, it's a bloody fast way to switch between desktops
Cheers

I believe the limitation isnt the hardware but rather the software at this stage. Word is that the maemo 6 will have multiple input etc. Interesting to see what you discovered though. Perhaps a hack is doable.

I like that, moving between desktops is quick, and funky

No, the effects seen here are just a side effect of how resistive touchscreens work. The n900 hardware does not support multitouch.

What's happening is the location of the detected pressure is just changing rapidly (due to the two inputs) causing the swipe. When both fingers are pressed, the screen reads this as an input somewhere between the two, not as two separate inputs. In some cases it might be possible to infer that two fingers are involved, but I think this would be of limited utility.

Useful trick for desktop switching though

I thought a resistive screen meant that pressure was needed to be applied?

Lol ya...what i meant was that it recognizes the degree of pressure..the harder you press..the closer the display moves toward the respective point

It's nothing new, all resistive screens behave like that.
Used it on the N97 to scroll faster in Gravity by removing one hand a small time before the other.
It's been exploited on some devices to allow multitouch (the 5800XM had a video uploaded showing it, but nothing else, and it was forgotten.)
Windows Mobile had an app that was being developed for it and exploited the feature, but I've never heard of it since it was announced: http://www.youtube.com/watch?v=A77VD9nKGDw @ 1:28 (iZoom)

Thanks for the info..Can you check if the n97 screen responds differently to different amounts of pressure? According to engadget, nokia has just filed a similar patent..

Isn't this just a characteristic of resistive screens? N97 does the same thing.

Though I had always secretly wished, (when Jussi said at ODZ) Maemo 6 will have multitouch and N900 will have Maemo 6 that secretly there's a multitouch screen.

Yes, again, all resistive screens are affected by pressure, cause it depends on two films pressing on each other, and pressing harder on one area will cause the screen to detect a press there (or closer to it)
My old HP iPAQ HX2795 does the pressure thing too.

As I said before, it is.