I run Attract Mode on a dedicated machine that stays on all the time, but I was finding that the default screensavers suck up a lot of CPU.. upwards of 50% CPU utilization or more in the collage modes. Normally my TV is turned off, so it seemed like a waste to be using that much CPU when no one was actually watching it. So I've made a custom screensaver script that adds a "basic mode" that kicks in after a specified timeout (configurable), which either cycles through a slideshow of artwork (also configurable), or just blanks out the screen entirely.
I really like the video/collage screensavers, so this doesn't replace the entirely; rather, it will run the default screensavers for a specified amount of time, and then will switch to the basic screensaver afterwards. That timeout/delay value is configurable in the screensaver settings.
Once basic mode kicks in, the CPU usage drops down to 1%, which allows the machine to run cooler and quieter when it's not actively in use.
Just drop the attached screensaver.nut file into your ~/.attract/screensaver folder and it will override the default screensaver.
Hopefully this will be useful for others as well!