BuddyPress.org

Bear in mind the original code is simply a modification of the ‘related posts’ code from WPRecipes (http://www.wprecipes.com/how-to-show-related-posts-without-a-plugin) with additional modifications from elsewhere on this support forum (forgive me, but I can’t recall where I picked it up from).
My coding isn’t the best in the world, but I know what I needed to achieve so feel free to tidy up, etc.

In theory, you could use the extended profile to gather all sorts of information (location, language, favourite food) depending on your member base and site content and then modify this code to deliver highly personalised content based on this meta data (as long as your tagging is in place).

Feel free to use and abuse, like I said it a combo from various sources so I can’t claim any rights to it! Go forth and personalise!