Couldn't find a post about this so thought I'd mention it. SXM gyrocopter operates from Grand Case airport and offer sightseeing flights around the French/north part of the island. They fly a tandem two seat gyrocopter, pilot in front, pass in rear seat. Open cockpit. I went on the 30 miniute flight and it is a truly exhilirating experience - assuming you are OK with heights and a bit of breeze and engine noise etc. You fly lower than a typical helicopter flight and quite slowly, the views are pretty special. Availability is weather dependent, the pilot is looking for not too much wind and no chance of rain so you get the best experience. If you want you can ask to take the controls for a bit as well - it's actually pretty straightforward once you are up there to climb/descend/turn.
www.sxmgyrocopter.com for info and reservations, in my case our hotel made the booking. One tip, you will need your passport to go through screening at the airport to get airside (in a pinch a driver's license may do but recommend a passport).
Dave