[UPDATE meanwhile you could get multitouch support, check http://www.ceh-photo.de/blog/?p=320]
So after some days of struggling with the touchscreen configuration I works very good (only singletouch).
The problem was out of the box the touchscreen is detected as a touchpad in ubuntu 10.10. It is a problem in the xorg-evdev driver (Version) 2.32. To fix this problem you need to patch the 2.32 or build and install a newer one.
I tested both posebilities and decided, that using a newer evdev driver is the easier and better way.
If you know what you need to do it is very easy operation.
Tutorial for Ubuntu 10.10:
sudo apt-get install build-essential xutils-dev xserver-xorg-dev autoconf autotools-dev libtool
# I don't know why it is not working with this modules installed -->bug?
sudo apt-get remove xserver-xorg-input-evtouch xserver-xorg-input-tslib
tar xvfz xf86-input-evdev-2.5.0.tar.gz
sudo make install
After a reboot the touchscreen should work fine in single touch mode.
For getting a right-click use System->Preferences->Mouse->Accessibility
I tested this solution on Ubuntu Desktop and Netbook Edition. On netbook edition(unity) I have some problems of clicking the application icons on the left bar. On Ubuntu desktops everything works fine.