#python
import webbrowser
a = ['http://www.google.com/reader','http://www.yahoo.com/','http://www.facebook.com/']
for x in a:
webbrowser.get('firefox').open_new_tab(x)
You just need to copy and paste that code into a text file and save it as something like "opensite.py" (better to use the .py extension)
Make it executable running the following command in terminal:
sudo chmod a+x opensite.py
Run it either in the command line with
python /path/to/opensite.py
Or create a launcher (you can do this in Ubuntu easily by right clicking on the desktop)