I’m a big fan of some of the practices of XP (eXtreme Programming) and, especially, pair-programming. No matter what flavor of pair-programming that you prefer, it involves two engineers sitting down at the same screen and solving the same problem together. One of the biggest benefits that you get is a fresh set of eyes on a problem, and of course, you now have two engineers who have “touched” the codebase instead of one. Sometimes you can have one engineer write the code, and the other write the tests and the comments. No matter how you slice it, it’s all good stuff.