One of the more frequent questions that I see is how to do interesting transition effects for applications. So here's how, first of all prototype your algorithm. Here we're going to use a page folding to visualize transitions as turning of pages. So that it looks like this:
Then we figure out how to adopt it to application. The trick is how to get contents of an application without extra repaints. In Qt the contents of top-level's is buffered and there is a private but exported way of fetching that contents (not fully platform independent at the moment). The example #2 shows how to grab the contents of the window without extra repaints and copies and use it to implement the effect, so it looks like this:
The forms were taken from Kate config dialogs so they're real config pages (hence also why they're, well, not too pretty). The effect is fully animated so to get a better idea of how it looks you'll have to look at the ogg file provided here. It's also worth noting that this effect is very efficient and works smoothly with virtually 0 cpu usage.
As mentioned in the last blog, to see more examples and code for this one visit Graphics Dojo. The above mentioned examples are at the examples 2 page.