Message Mate Plugin

Is there a way to use WordPress ‘code’ to produce a live ‘messages’ system on a website. Thereby a visitor to a website can leave a message for the webmaster that is sent for approval and then displayed in the sidebar or centre column afterwards. I do not mean a shoutbox.

As seen on the British Army’s attempt to scale the West Face of Everest last year here. After a visitor’s message is approved the most recent then appear on the site’s homepage, which is exactly what I’d like to do for my own Gobi expedition this Summer.

I suspect this can be done using comments and wordpress coding or does a ‘message mate’ plugin already exist?

All the Best. Steveo