Sure. I have a dashboard display on a form. The columns are years, and the rows are data rolled up by year. It would be great since I have the detail by quarter to be able to hide and unhide rows or data. This is a fairly common thing in data displays and visualization.
It would be great if the conditional formatting was expanded to allow hiding row and even columns. In addition to the above use (which makes some really great presentations) it provides the added benefits for general form display of hiding rows (or columns) for fields that are hidden or the creator does not want displayed without leaving lots of space gaps (forcing unnecessary scrolling in some cases)
This seems like a lot of benefit, provides a lot of flexibility and allows users to do some really great stuff.
If you have more questions, let me know. But this functionality would be really helpful and others seem to be asking for the same thing.