Yes and it will save you a ton of time during testing.

MACINTOSH: Set up a "Hot Corner" to launch your screen saver.

Open the the Screen Saver settings panel from the Apple menu by selecting the "System Preferences..." menu item to open the System Preferences window, then clicking the "Desktop & Screen Saver" icon and the "Screen Saver" tab button.

In the lower right hand corner you will see a button called "Hot Corners...". Clicking on the button will open the "Active Screen Corners" sheet. Click on one of the four corner pop-up menus, select "Start Screen Saver", and click OK. Now when you leave your mouse in the corresponding corner the screen saver will launch.


WINDOWS: Run our free "Sleeper" ultility to launch your screen saver.

On Windows you can launch a screen saver without waiting for the system's timer to expire by using our free "Sleeper" application. Sleeper can save you time when you are testing your screen saver.

Click here to download a collection of Windows screen saver utilities. The collection of Windows screen saver utilities includes:

sleeper.exe - activates the current system screen saver.
activeSaver.exe - sets your saver as the active saver.
opener.exe - opens the display properties control panel.

To use Sleeper, first unzip and install it onto your desktop or somewhere that's easy for you to find. To run Sleeper and launch the active screen saver, just double click the Sleeper icon. Your screen saver will launch instantly.

You can also run Sleeper as a command line application from the MS-DOS prompt. Just type the app's full path name and hit enter.
Example:
C:> C:/Windows/Sleeper.exe

This can be helpful if you want to build your own installer or need to launch a screen saver from within another application.