I'd like to reserve a section of my desktop for placing all my widgets. So when a window is maximized it does not get mixed up with the widgets.
Since there's one for Windows, I am guessing there is one for Gnome.
At least Window Maker has widget support built-in (called DockApps). A quick sample(1) can be viewed at Window Maker documentation.
Another choise, if one isn't ready to switch window manager yet, is the Docky(2) frontend for Gnome Do(3) which can be used at least as a dock.