I like to putter around with some of the lesser known tools - and play with the camera in SL.
One of the rendering options in the Client menu (formerly the Debug menu) is to view your surroundings in wireframe. You can get some interesting effects this way.
If your Client/Debug menu isn't visible in your options, click Ctrl-Alt-D in Windows (sorry, maybe someone can comment on the Mac command!) and it should appear along with the Server menu. Happy debugging! ;)