Can I make a node reservable? Is it possible to make a node reservable (for users that do not have rights to edit/add content, or even anonymous users)? The node in this case is a "timeslot" for a service.

So there would be lots of nodes and each node could only be reserved once. At reservation time the person making the reservation should give his/her contact details. No payment or anything like that is made at this point.

I found the tutorial about Using webfom 3.x to reserve items/nodes in Drupal 7 (using the Webform module to "reserve a node"), but not sure if it is the best way (I am looking into it).

Or if anyone can just point me into the right direction, would be appreciated.
you can try the reservation API