Restore backup solution for busy sites

Question

Today one of my users went and deleted the root of an Organic Group and wiped out all of the child nodes from that group and it's associated menu entries.

I have a backup, so I can restore, but in the time between I was informed of the problem and when it occured, other people were making updates to the site - so it wouldn't be as simple as just falling back to the last backup.

Happily, it was a simple group which is easily re-creatable - but I know one day, someone is going to delete a node which isn't trivial to re-create.

We've all had a colleage (or done it ourselves) who has called the local sysadmin and said "I accidentally deleted e-mail xxx - please restore it" - and the sysadmin goes and does it. My question is: How can I do this for a Drupal site? Ie. I want to be able to restore a node, or a set of nodes without completely rolling back.

Any ideas? Would love to hear from people with experience in dealing with this kind of problem. I can see there are modules such as "Feeds" and "Node Import" but I'm looking for peoples opinions on best solutions based on their experience.