Visual Studio keyboard shortcut to automatically add the needed 'using' statement

Ctrl + . shows the menu. I find this easier to type than the alternative, Alt + Shift + F10.

This can be re-bound to something more familiar by going to Tools > Options > Environment > Keyboard > Visual C# > View.QuickActions

Alt + Shift + F10 will show the menu associated with the smart tag.

I can highly recommend checking out the Visual Studio plugin ReSharper. It has a QuickFix feature that does the same (and a lot more).

But ReSharper doesn't require the cursor to be located on the actual code that requires a new namespace. Say, you copy/paste some code into the source file, and just a few clicks of Alt + Enter, and all the required usings are included.

Oh, and it also makes sure that the required assembly reference is added to your project. Say for example, you create a new project containing NUnit unit tests. The first class you write, you add the [TestFixture] attribute. If you already have one project in your solution that references the NUnit DLL file, then ReSharper is able to see that the TestFixtureAttribute comes from that DLL file, so it will automatically add that assembly reference to your new project.

And it also adds required namespaces for extension methods. At least the ReSharper version 5 beta does. I'm pretty sure that Visual Studio's built-in resolve function doesn't do that.

On the down side, it's a commercial product, so you have to pay for it. But if you work with software commercially, the gained productivity (the plug in does a lot of other cool stuff) outweighs the price tag.

Yes, I'm a fan ;)