Quick description: imagine you use apps like 'conky', 'root-tail' or such and you'd like to have them always in sight for whatever reasons. Now think about what happens when you maximize a window...it maximizes all over your workspace which pretty much covers all those nifty info you'd like to watch.
Since fluxbox has this little "prevent-from-max-over-feature", I used to use 'gkrellm2' for viewing my cpu and my memory usage AND, more importantly, as a delimiter for maximized windows. The only problem is that 'gkrellm' runs unstable for me sometimes and it's quite "big" for my little task. 'conky' for example does the same with less memory/cpu usage and I can customize it much more than 'gkrellm'. The only problem to face was that I need to run something in the slit to prevent any window from maximizing over it to keep the space free for my information display or rightclicks to pop up the menu. Thisfor I used 'gkrellm2' as mentioned earlier.
Now there comes ak|ra who wrote this little dockapp that does absolutely nothing except for sitting in the slit :) . You can find space_dapp.c in ak|ra's bits section. The big advantage is that this app consists only of one single C file and consumes almost none of my resources. If I run it I set the width to my needed space and the height to 1 pixel, then place the slit to "bottom/right" and I finally have an invisible delimiter way slinker than 'gkrellm2'. Works for vertical or horizontal slits because the dimensions of the space-dapp are freely selectable. The easy it seems, the easy it works but hell...it DOES work :)here you can see what i actually use it for: