Select your screensaver with Screen Saver Menu
Here's a handy little tool. Screen Saver Menu adds an item to the Finder's menu bar that lets you quickly select and launch any installed screensaver. What's more, you can use it to browse your iPhoto albums and immediately launch any of those as a screensaver. Finally, you can enable a screen lock for when you're not around. Now you can free up that hot corner you've set up for something else.
Screen Saver Menu requires Mac OS 10.3 or better and is $5 shareware.