Hi Philip,

If you're looking to do it over the summer, all of the karate schools in the Geneva area are closed, except for one: Shung Do Kwan Budo (http://www.sdkbudo.ch). They do Shotokan here, and most of the people in this school are rather advanced (green belt upwards).

Otherwise, the karate schools open in the summer. Here's a pretty exhaustive list of the schools:

http://www.club-association.ch/acgk/partenaires/rive_gauche.html

http://www.dojoguide.org/en/search/?land_id=1&region_id=&kampfkunst=&detailsuche=true

I'm doing Shito-ryu Karate (and enjoying it quite a lot) and would be happy to give you my experience with the school.

Oops, I actually meant

"Otherwise, the karate schools open in the fall" (when the academic year starts, this year around August 30.)

I tried this club and liked it. http://www.ipponkarateclub.ch/tivoli.shtml I'm 24, but trained with the juniors to get some more fighting, so I don't know if the adult classes are good. Unfortunately they have summer vacation now so I only got to go a few times, but I will go back  when they start up.