I had some troubles getting information on how to watch my slingbox on ubuntu. I was unable to get any support from Slingbox as they only support windows, android, and apple platforms. Here is how I got it to work.
1) Create a slingbox.htm file with
as the contents
<iframe src="http://slingplayer.slingbox.com/embedded/slingplayer.php" frameborder="0" width="1440" height="900"></iframe>
2) Create a new shell script that will reference the .htm file you just created.
I created slingbox.sh in /home/USERNAME/Documents
Make the .sh script executable by right clicking on it, selecting permissions tab, then select "allow executing file as a program"
xdg-open /home/USERNAME/Desktop/Slingbox.htm &
2) Now create a .png file and save it to the same directory. I just googled for the slingbox logo and captured it with shutter. "Sudo apt-get install shutter" (this is a cool program)
3) Create a "slingbox.desktop" file under /user/share/applications
Change permissions terminal :
sudo touch /usr/share/applications/slingbox.desktop
sudo chmod a+x /usr/share/applications/slingbox.desktop
GUI : Navigate to /usr/share/applications
Create new text document named slingbox.desktop
Right click change permissions as mentioned earlier
4) Add the following text to the slingbox.desktop file
*REMEMBER TO MODIFY YOUR PATH TO YOUR USERNAME*
Reboot and you should now have a slingbox icon on your unity search, and should launch with your default web browser.
Here is a pic