Edit /etc/apt/sources.list to add the VirtualBox repo and enable contrib and non-free for your favorite Debian repo line. The lines we care about look something like this:
deb http://mirror.rit.edu/debian/ squeeze main contrib non-free
deb http://download.virtualbox.org/virtualbox/debian \
squeeze contrib non-free
Grab the Oracle apt signing key and install it with a:
sudo apt-key add oracle_vbox.asc
Run a quick update for aptitude (or apt-get if you prefer):
sudo aptitude update
Install the needed packages (Java6 JDK [you supposedly only need the JRE but I'm using the JDK as well], VirtualBox 3.2, and ia32 libraries [only on 64 bit]):
sudo aptitude install sun-java6-jdk virtualbox-3.2 ia32-libs
Grab a copy of HP/Palm's novacom and the actual SDK (be wary, it's 185MB in size) in deb format.
And, finally, install both of those:
sudo dpkg -i --force-architecture \
sudo dpkg -i --force-architecture palm-novacom_1.0.64_amd64.deb
As the novacom package provided by Palm/HP uses Upstart as found on Ubuntu (Debian doesn't), you have to start the novacom daemon yourself. It can be found in /opt/Palm/novacom/novacomd. Novacom should allow you to push apps into the virtual machine for testing, Palm/HP don't want you messing with the file system in weird ways.
To launch the emulator, fire up a console and run
palm-emulator. It will first build the virtual machine and then launch it. Use the escape button (on your keyboard) to go back, the end button acts like the button on the phone, and home does something (sort of like end, but not sure why it's different). Clicking and dragging are just like your finger would do.
Pretty picture below: