There are several optimisations you can make to preserve screen space on small screens. Having only 1 GNOME panel is definitely an improvement.
Global Menu Bar
You can customise your GNOME panel to contain the menu bar for all application windows (except those that don't work with it - the main ones are Firefox and Open Office). Obviously this makes much more sense if the GNOME panel is at the top.
To enable this, install the package: indicator-applet-appmenu. Once installed, right click the panel and click 'Add to Panel...' and choose the 'Indicator Applet Appmenu'. One caveat with this is that applications with huge menu bars (such as GIMP) may not fit on the panel at low resolutions.
Maximus is software that automatically maximises windows and removes their title bar when maximised. It was designed specifically for netbooks and used to be part of the Ubuntu Netbook Remix.
To test it, you can press Alt+F2 then enter
maximus. To use it permanently, you will probably prefer to add it to the startup applications (
If you ever want to un-maximise a window, you can't use the normal window buttons but you can still use Alt+click+drag down. The window border will then be re-added to the window.
You can get a similar effect by configuring compiz so that window decorations disappear when you maximise a window. This is good if you don't want windows to maximise automatically but want to save space once they are maximised.
Docky is a launcher and dock.
Its main advantage in terms of saving screen space is its Intellihide/Window Dodge feature. I find this much better than the autohide of the GNOME panel because it seems that it shows at the right times more. Docky also reduces space by using icons instead of names for windows and grouping windows by application. These are the settings I use:
These settings can be accessed by clicking the Docky anchor icon, then clicking on the dock to configure. Docky requires compositing to run. If your netbook can't run compiz, enable compositing in Metacity.
Window selector is a panel applet that shows all your windows in a menu. This can save a lot of space if it is used instead of a window list at the expense of requiring an extra click.
As far as I know, this applet is installed by default. You can enable it in the usual manner.
I personally use the all of these to make best use of my smallish (13.3") screen. I have 1 panel, which I keep at the top.