FYI, there's an easy way to make it so that the screensaver doesn't come on.

System Preferences -> Dashboard & Exposé

(yeah, odd place, I know)

Set the bottom-left screen corner to "Disable Screen Saver". After doing that, you can move your mouse to that corner to stop the screen saver from coming on.

I'm not sure if there is a similar option for disabling sleep, though.