I would start a check list / action plan for this travel and arrangements project.  I would then assign roles and responsibilities ie:  Mr Squatter - Action:  Contact Legal, etc.  My boss would endors it since it would be taking away form time I could be working on a project for him..  I had a co-worker once that always leaned over the counter in a cube I used to sit in.  One day, my boss came out and told him he was going ot start charging him rent everytime he saw him there.  It worked, the guy quit hanging around.