If you are trying to create a diagram from a complicated connection, try Diagrammr. Instead of trying to draw the lines and crossing them from one point to another point, you can just write it out and let the program draw the diagram. Unfortunately it seems like the program is no longer working. Tested the program with couple of sentence but diagram does not appear. It is unfortunate because it seems like an interesting idea.
If you are interested in the program, perhaps you can try to make the program work and redesign it into an app. You can find the open source code at the about page. This program might create some unexpected money making opportunities with some twists and changes. There are still lots of rooms to expand. The question is do you see an opportunity here. Remember that lots of successful entrepreneurs and billionaires build their fortune by taking over failure businesses or ideas. I suppose many already started taking action as I’m blogging about this. Opportunities will only strike on those who take action. It is easy to have an idea, but it is the one that puts it into action for results will gain success. (Or failure. But that’s the risk we need to take)