I have figured out a way to use the NoLimits screensaver to feel like you're actually riding space mountain.
First, you need SpaceStation77's space mountain recreation, which you can get here:
http://www.coastercrazy.com/track_excha ... ?tid=11736
or here:
http://www.coastersims.com/viewcoaster.asp?id=15846
Second, you need to download these two audio files:
http://jcoaster95.com/Documents/SM%20ex ... 0audio.zip
EDIT: if it says the link is broken, copy and paste the url.
Extract them into your music folder (it doesn't matter which one).
Now, go to your windows screensaver settings, and change the screensaver to "NoLimits Screensaver 1.6".
Click on "settings".
Add "Space_Mountain2005_DL_SS77" to your track list. It should be the only track on the list.
Add "30 sec sfx" and "California Soundtrack" to your music list in that order. They should be the only 2 files on the list.
Change the settings to:
GENERAL:
statistics bar:
-unchecked
Exit Screensaver:
-both unchecked
When to Change Tracks:
-do not change tracks
Sound and Music:
-play music-checked
-music volume-default
-sound volume-50%
VIEW SETTINGS:
Views:
-only "ride view" checked
When to Change Views:
-do not change views
Seat Assignment:
-front seat only
Special Effects:
-both unchecked
click "ok"
Now turn out the lights and click preview!
When it loads, press the "t" key once. You may need to speed up or slow down the speed during the ride.