I have just created new project named netdgrm (code.google.com requires lower letters for projects names, so I use this convention here too). It’s simple graphical editor for diagrams of computer networks. Project’s page is here. There is a screenshot and first pre alpha 0.0.1 release. It’s very stable but lucks “few” features. Unfortunately it is a plug-in for Eclipse platform and you have to install many dependencies to get it working.