I really agree with #1. If you're talking about work at lunch, you're probably bitching. We all need time to bitch, but you get tired of it. And I don't care about what my coworkers' kids are doing, or what work they need to do around the house, or what sports they're watching, etc, etc.

I like to spend some of my lunches reading a book. It's relaxing, keeps me from thinking about work, and let's face it, when you get busy, reading for pleasure is often one of those things that gets pushed aside.