Ask HN: When and how to outsource software development?

I'm trying to find out more about outsourcing software development (as in, paying engineers that aren't your employees and possibly live in another country).

As an engineer in Silicon Valley, I know very few people that outsource their development and haven't heard many success stories (I recently learned that fab.com is built by a team in India that used to be a development agency, though). I do, however, see a lot of potential to accelerate or reduce the cost of development for certain types of projects.

Would you mind sharing your experiences with projects that went well or not so well? Is there ever a good reason to outsource development, even if you have in-house developers?

How do you make sure the development team is any good? Or, how do you find a good team?

Is there any forum (in real life or online) where people who outsource development and development teams congregate and discuss best practices/challenges?