Is there a feature in SMF that allows the poster to create a "whitelist" which only allows only certain members to view the post?
cheers,
hindian
No there isn't, except by putting it in a board where only some users have access.
Not likely to be added as a core feature any time soon either.
If you need this, please feel free to make a post in Mod Requests (http://www.simplemachines.org/community/index.php?board=79.0) with more details of exactly what you need (there is a sticky topic in that board on what details would be necessary)