The only one I know off is keeping ALT pressed when your in the scene window. The cursor will change to a camera and when you press the left mouse button and move the mouse, the scene / camera view will rotate.

There may be more like this.

Artwork and 3DToons items, create the perfect place for you toon and other figures!

http://www.renderosity.com/mod/bcs/index.php?vendor=23722

Due to the childish TOS changes, I'm not allowed to link to my other products outside of Rendo anymore :(

Food for thought.....
https://www.youtube.com/watch?v=pYZw0dfLmLk