If you use Ubuntu like me and have an HP printer then you may want to check your printer ink level from time to time. For HP printers the solution is available in the repositories in the form of HPLIP (Hewlett-Packard’s Linux Imaging and Printing), which is installed on Ubuntu systems by default. In the case of Ubuntu 8.04 we only need to install the graphical interface.
Make sure HPLIP is installed on your system with Synaptic and search for hplip.
You can either choose to install hplip-gui with Synaptic or use apt-get.
apt-get install hplip-gui
After the install you can find HPLIP Toolbox on System > Preferences > HPLIP Toolbox , and check you ink levels.