I would like to draw diagrams using Open Office but I didn't find any installed by default. What I am exactly looking for are diagrams that look like the ones that come with MS Office 2007/2010 (like Pyramid diagrams, Star diagrams etc.).

Any idea? A plugin to install? Otherwise are there any online services that can do it? (I have tested Cacoo and gliffy but they don't really offer the diagrams that I am looking for).

Thanks!