Allow users to "mark" a node

I have a site which has various surf spots as nodes. I would like users to be able to have the ability to check these nodes as "surfed here".

I also like the idea of adding these locations to a user's favourites list - much the same principle I guess.

At some point the surf spot will show a list of surfers who have surfed there along with the opposite relationship on user's profiles.

Any ideas how this can be done - in a an easy user-friendly way. Ideally just a check box on the node page.

Many thanks,
Chris