Creating a library that contains instance members

In regards to my a little to late discovery that static libraries (obviously) can't have instance members, http://stackoverflow.com/questions/708155/how-to-reference-property-on-library/708263#708263, is there a way to create a shared library that contains both instance and static members?

On way that probably works is to create a class file, save it to some shared directory and reference it from multiple projects. Is there a better way?

From stackoverflow

• I just read an excellent blog post this morning with a nice writeup about sharing code:

  http://www.mobileorchard.com/code-sharing-via-static-libraries-and-cross-project-references