asking for openCV on beagleboard howto


I was trying to run some examples of openCV on my beagleboard
I have mplayer and logitech camera running on it.
However I had no luck (see errors below)
Am I missing something?

As well can anyone point me to some info how to build and run openCV
application on beagleboard?
And yes, it's completely new to me, and I have a book and I did
google, but could find anything to move me ahead.


root@beagleboard:~# uname -a
Linux beagleboard 2.6.29-omap1 #1 Tue May 19 12:23:42 CEST 2009 armv7l
root@beagleboard:~# camshiftdemo
Hot keys:
  ESC - quit the program
  c - stop the tracking
  b - switch to/from backprojection view
  h - show/hide object histogram
To initialize tracking, select the object with mouse

(Histogram:3429): Gtk-WARNING **: cannot open display:
root@beagleboard:~# blobtrack

(blobtrack:3430): Gtk-WARNING **: cannot open display: