OpenCV - Where is it? How to test it?

The JetPack 2.2.1 installs the prebuilt OpenCV4Tegra library.
I then followed the instructions here:
http://elinux.org/Jetson/Installing_OpenCV
…and ran the commands below to manually install the prebuilt packages:
sudo dpkg -i libopencv4tegra-repo_2.4.13_armhf_l4t-r21.deb
sudo apt-get update
sudo apt-get install libopencv4tegra libopencv4tegra-dev

That last command resulted in the following: “already the newest version” so I’m not sure why it was recommended. (Does anyone actually review and update those elinux sites??)

OK, so now what? How do I test the OpenCV installation?

Following the instructions on that same site:
cd ~/opencv-2.4.9/samples/cpp
…results in “No such file or directory” which seems obvious since I doubt that version 2.4.9 is correct. However, fishing around in my TK1 file directory I cannot find any reference to an OpenCV folder, only the original folder containing the deb file.

So now what? How do I find where OpenCV is on my TK1? How do I test the samples? How do I update my path so that can use OpenCV with code I already have?

Most of sites out there gloss over the really basic stuff for noobs like me. =)
Thanks in advance for your help!

I just installed JetPack 2.3, same question as above --> Where is OpenCV?

After the JetPack is successfully installed, I can open a terminal window, type “python” to get the python prompt. Then, if I type “import cv2” I get the following error:

ImportError: No module named cv2

So, I’m asking again, where is OpenCV and how do I access it to use it?