Crystal Xcelsius has been the first BI tool for me to learn in my new job. It's a great piece of software to create interactive "what-if" dashboards. It even lets you misuse itself in a playful fashion. See the following video (sorry about bad quality).
In the video, I first open a PowerPoint document that contains a Flash model (blue data points and play button). After starting a slide show, the play button allows me to spin data points around a 3D ball (rotating text "ESPOO" is the name of my home town).
How did I do it? See the following flowchart about the Xcelsius development process (the Flash model of course works in a browser too).
You always build an Xcelsius model based on an Excel spreadsheet. If I simplify it a little, some Excel cells are input cells (in Xcelsius, you make play buttons, sliders, check boxes, radio buttons, combo boxes, or text boxes to change their values) and some are output cells (in Xcelsius, you create charts using those).
The method of using Excel and Xcelsius together means that you end up having specifications in two places. The larger the Xcelsius model grows, the more dependencies you have between the two. Adding a third component--online database access to Excel--is possible as well. As I so far don't know the best practice to build a large Xcelsius model, I consider you rather build several independent small Xcelsius dashboards instead of a combined one.
To finally show how I created the 3D demo, below you can see the Excel speadsheet. Original data points are in B13:C62 (for example lines 13 to 25 draw the letter "E"). Cells I13:J62 are output cells for the XY chart. B5 is the input cell for the Play button.
The following image shows Crystal Xcelsius in the designer mode. The Play button is commanded to increase its value from 0 to 359 degrees continuously (auto replay selected).