I used Olympic-style lifting (Snatch, C+J and related exercises) for years to improve my other sports. I will take the contrarian argument on lifting to fix back pain. I think they're excellent when performed properly as everyone is saying here, but that's a heavy qualification. Especially if you start with back pain.

If you have access to a proper coach or club, great, go for it. But if that's the case, you already know it's a good exercise and where to find the proper coaching that is absolutely essential to getting results and avoiding injury.

Whereas, if the idea of lifting is relatively new to you and you're figuring it out from reading Hacker News, you need to be very careful before taking it up. Most gyms have personal trainers that don't know 'squat' about proper lifting form and less about dealing with pain.

If you think the software industry is bad for snake-oil, it's only because you haven't been exposed to the world of gyms, personal trainers, and supplements. I wouldn't recommend anything except a University program or gym devoted to actual competition in the Olympic disciplines (not powerlifting or body building of any kind).

Okay, enough ranting. My positive recommendation is rock climbing, specifically bouldering. Find a gym in your city. It's a fun, positive environment, it has plenty of attractive and engaging people of every gender and orientation (there's a fabulous gay climbing club in Toronto). Your core is going to get strong in a hurry.

And if you fall in love with the sport, it will take you around the world. See you in Thailand some time.

:-)