Read the Ulteo forum
I link and give short quote here but officially Ulteo
developers don't recommend that one add things now.
They plan to make it possible in future but it is still a Beta.
In the forum the user named froogle wrote how he did it.
Wed May 21, 2008 12:27 pm How to install software on Ulteo Virtual Desktop
I'll start this off with a disclaimer. This may not be the approved Ulteo way of doing things. It may also cause some problems in the longer term. But, it's worked for me so far so fingers crossed. Also, these instructions assume you have only just finished installing ulteo and not changed anything (like passwords, or sudoers)
I also found another description on how to do it.
Ulteo does come with enough programs to play with and keep the typical user satisfied. However, there are thousands of other programs that can be installed and run on the system. In order to get these downloaded and installed as painless as possible, perform the following steps.
1. In Ulteo, click the "Start" button, All Applications, System, and Konsole. This will open a console Window on the Linux VM.
2. Type "cd /etc/apt" in the shell and hit enter.
3. Type "su" followed by the password of "root"
4. Type "pico sources.list" to open a new text editor window
5. Copy and paste the following into the shell window:
Read the whole text at that url.
So there you have two ways of doing it. Not recommended but seems to work.
I use Ulteo but have not tested it cause me are not good at doing such advanced
things but thought you guys give up too easy. Just using google me found these
descriptions. So not always but often somebody has had the same need and maybe
share how the did it One just have to use google to find it.