My Problem? Pure, unadulterated boredom...

I'm not sure if there are any rock gyms in or near Napa, but indoor rock climbing is usually how I spend my evenings when I have money for a membership and time to go. It's a great workout for the core, but since you're not constantly on the wall climbing and have a bit of down time between routes, it's also a somewhat passive and relaxing activity. Don't think you have any upper body strength to even cling to the rocks? Neither do I, haha. If you can find an experienced climber or two (or even a semi-experienced climber) to give you advice on the routes, you learn to use your body to climb without using too much arm strength and utilize more skeletal strength. Climbing can even be an individual activity if you do bouldering and not top-roping, which requires a partner to help with the ropes. Mind you, one of the side effects of climbing (that some might consider unattractive) is calluses on the palms of your hands. Personally, I love having those calluses :] They feel great to me.

If there are no rock gyms nearby or this just seems totally undesirable, yoga or pilates or fusion/yogalates/piyo are fantastic. They're all great workouts and are very relaxing (at least for me). They're not as intense as lifting weights or running or doing a zumba class, but they're still pretty physically demanding. I've also started to form some friendships with the teachers and other people in my classes :]

Hope this helps~