Howdy- Just so I feel like I've actually added some signal to today's discussion, I wanted to point folks at:
http://www.ccs.neu.edu/groups/systems/howto/howto-snapshot.html
This is a document I wrote when we first got our NetApp explaining snapshots to our user community and how they are used for online file recovery. Feel free to use it with local modifications if you ever need to publicize same.
Respectfully, David N. Blank-Edelman Director of Technology College of Computer Science Northeastern University