ReSharper Tip of the Day: Adding Usings and References
When you go to use a type that is not added in the references, you can type out the complete name.
And ReSharper will know it needs to add, in this case, System to your using statements. Press ALT + Enter and it will add it for you.
If the name is ambiguous it will ask which one you want.
If you don’t even have the assembly referenced it will ask you to add that too.
WARNING: This will make you lazy with remembering which assemblies and namespaces are home to which classes.