David wrote that Spark is like a LT Version of Revit. Great for colaboration....
Might be worth while talking a look and downloading it to try it out, you'll need to create a log in to access Autodesk Labs if you dont already have one.
check out David Lights blog http://autodesk-revit.blogspot.com/
System Requirements: http://labs.autodesk.com/utilities/spark/system_reqs/