Visiting Paris in July or August is a love-it or hate-it experience.
Either you completely dig the fact that most Parisians have "foutu le camp," or you prefer to wait till September for "la grande rentrée" when the weather is still fine but school's started up again and la belle France is back at work.
Some of us fall into both camps. In July and August, it's much easier to get reservations at restaurants. First-run movies are not usually sold out. And the subway is just a little easier to get through. Whenever you visit, there's a fun little knot of gay bars to tour that are popular with visitors and locals (who like visitors) at the intersection of rue des Archives and rue Sainte-Croix de la Brettonerie in the super gay-pouplar Marais section in Paris' 4eme arrondissement.
The usual suspects are the Open-Cafe at the intersection with its outdoor tables (and decent restaurant) and Le Cox Bar a few doors further south at 15, rue des Archives which attracts a more mature bear- and leather-friendly crowd.
Add to this tasty mix, the new Spyce Bar at 23, rue Sainte-Croix de la Brettonerie. It's a bar/club which is quite small but packed particularly on weekends. The crowd hasn't seemed to sort itself out yet, but expect to find a mix of men and women (many straight women). The music is high energy.