The shape combine function in PowerPoint 2010 is great. Here is an example of how you can create text that seems to be flying through a circle. The key is the create 2 half circles and send one of them to the back. In earlier version of PowerPoint, this was very hard to do. (See a review of PowerPoint 2010 here).
|Draw 2 circle shapes|
|Center them horizontally and vertically|
|Select the shapes, (inner last), shape subtract|
|Draw a rectangular shape|
|Same trick: select them both and do shape subtract|
|Copy and flip the half moon|
|Send the right half moon to the back and put some text|