It sounds like you are having a problem with auto-run. When I double click the 'arduino' file in Ubuntu it gives me the option to display, run, etc..., you may wish to look at your auto-run settings if you want to fix the problem of it automatically opening in OpenOffice. If you are familiar with the terminal you can open the program from there. Just follow this example.
//Install Java if you haven't already
sudo apt-get install openjdk-6-jre
//If you already have the file extracted then you can skip this step. This will download and extract the 1.0.1 software for 64-bit Ubuntu
wget http://arduino.googlecode.com/files/arduino-1.0.1-linux64.tgz
tar xf arduino-1.0.1-linux64.tgz
//You will need to 'cd' into the extracted arduino folder. I assume that you are following the previous step.
cd arduino-1.0.1/
//Now just execute the program
./arduino