Is it possible (not a safety hazard) to put it just outside your cube?  That way it's there when you need it, just needs to be turned around and bumped into the cube.  Otherwise, it's in the "hallway" and not so inviting for folks to sit in.

If not, then the option of politely asking if you can help them, perhaps with even the more noticeable hint of turning off your monitor while you talk to them, might be the way to go.  Do you have any catalogs that you order supplies from that might be able to sit on the chair on a day-to-day basis?  Just trying to brainstorm an ideal way to get the chair vacated when you're not wanting the unwanted visitor.

CountriGal
Peer Moderator