Define a .NET extension method with solution scope

Question

I have a few 'helper' style extension methods I use quite regularly now (they are mostly quite simple, intuitive, and work for good not evil, so please don't have this descend into a discussion around whether or not I should use them). They are largely extending core .NET CLR classes.

Currently, I have to copy the 'ExtensionMethods.cs' file that holds my extension methods to each new project within a solution to be able to use them in multiple projects.

Is it possible to define an extension to work over multiple projects within a solution, or wrap them in an 'extensions' dll, or are they confined to the scope of project?

EDIT Whilst the 'dedicated project' answers are perfectly valid, I chose marxidad's as I prefer the approach he gives. Thanks for all the answers so far, and I have upmodded them all, as they were all good answers

Answer 1

If you don't want to create a whole project just for the extension methods, you can link the same file into separate projects without copying the file:

1. In Solution Explorer, select the target project.
2. Select the Project menu.
3. Select Add Existing Item.
4. In the Add Existing Item dialog box, select the item you want to link.
5. From the Open button drop-down list, select Add As Link.