Try doing this first:
This package should have been uninstalled when you removed hal, and installing it should fetch hal, as well as all other packages that are part of the netbook remix. If that doesn't work the code to download and install hal is:
sudo apt-get install ubuntu-netbook-remix
Please note that the Debian package is not compatible with Ubuntu (well, it may work, but it's unlikely.) So the above uses an Ubuntu package.
sudo dpkg -i hal_0.5.13-1ubuntu8_i386.deb
You may wish to try vanilla ubuntu to see if that detects your touch pad better. Also try 8.04 to see if that works better.