Organize Big Solutions with Solution Folders
If you have a solution that contains multiple projects (I had one solution with 14 projects), you should probably be using Solution Folders. Solution Folders recognize that the projects in a solution often belong in groups: keeping the Web projects separate from the middle-tier business projects, or keeping a class library close to its test project. Solution Folders let you make those groups explicit in Solution Explorer.
To add a Solution Folder to Solution Explorer, right-click on the Solution line at the top and select Add | New Solution Folder. This will add the folder and let you name it. After you've added your Solution Folder, you can drag projects already in Solution Explorer into the folder. You can then expand or collapse each Solution Folder, or even unload a folder if you don't need that part of solution right now and don't want to waste time rebuilding those projects. You can also right-click on a Solution folder and pick Build to compile just the projects in that folder.
This isn't a feature that you need if you keep the number of projects in a solution small; but once you pass some threshold number of projects (and that number will vary from one developer to another), you'll be glad it's there.
Posted by Peter Vogel on 02/24/2012