Here's another topic which I believe is important to educate more folks on, but I just haven't had the time to carefully write something up. As I was answering a question on the forum today, I realized that the answer might be good to share a bit more broadly, so here's a copy of that response. The question which has come up several times is "When do I dispose of a context and recreate it vs when should I keep the existing context around and re-use it?"
If you are building a rich client application then you may well want to keep a context around for the life of the application, but you need to keep track of how many entities you have in that context. It's all about understanding the overall pattern of your app. There are some extremes and a whole spectrum of possibilities across the middle.
As one of my high-school math teachers used to say, clear as mud?