omg... the shortcut wasn't as easy as i thought it would be... but finally it's working...

instructions:
1. download the zip-file and unpack the two files anywhere in a new folder in your MyDocs. for example: ~/MyDocs/randomvid/
(unplug usb cable)
2. open xterm and type "sudo gainroot"
3. type "mkdir /etc/hildon-welcome.d/dconfs"
4. in this folder you have to store your default.conf files named 1.conf, 2.conf, 3.conf and so on (you have to start with 1 and then incremental count up (2, 3, 4, 5,...))
5. type "cd MyDocs/randomvid/"
6. type "cp rvid.sh /etc/hildon-welcome.d/"
7. type "chmod a+x /etc/hildon-welcome.d/rvid.sh"
8. type "cp rvid.desktop /usr/share/applications/hildon/"
9. close xterm, go to your desktop and add the shortcut named "rvid".

it uses the terminal-icon. if you want your own icon do following:
1. place a .png with 48 * 48 px in /usr/share/icons/hicolor/48x48/hildon/
(for example: rvid.png)
2. open the rvid.desktop with a editor and change the icon-line to:
"Icon=rvid". save it.
3. you may have to reboot your device.

thanks go to:
fatalsaint for pointing me in the right direction with the desktop file.
(http://talk.maemo.org/showpost.php?p...7&postcount=66)
subcore for hack-around changing xterm to busybox.
(http://talk.maemo.org/showpost.php?p...9&postcount=11)
archebyte for changing the desktop-icon and some other neat work.
(http://talk.maemo.org/showpost.php?p...0&postcount=26)

edit:
it's normal that the terminal opens up, stays black and closes after a few seconds.
it's also normal that it may replaces the current default.conf with the same config - so your video may not change everytime you click on it. but hey... that's randomness ;D

EDIT: updated the rvid.sh with new code with generates random number out of date and checks which default.conf is used at the moment so the video is changed every time you click it
(code is available on page 4 where the instructions are given on how to do this random vid change automatically ^)