An idea I had but never really executed on was a mechanism for tagging documentation as "should be reviewed at least once every X months" - for things like setting up developer environments.

That way a team could be alerted if their documentation was due-for-review. One person gets assigned a task to review it. They look through it, update it if necessary, and either way put a "last reviewed by X on date Y" tag on it so people who read it can tell that it's still relevant.

At that rate you're better off buying some software that handles all this for you. Enter Microsoft Sharepoint. Yikes.