Newer technologies and the World Wide Web present opportunities for authentic writing never before possible. For example, I had students write opinion papers for ENG 101, as I usually do, but then they condensed their papers into a paragraph and posted them on a blog. Students were surprised to see that others had not only read what they had written but had responded to their ideas. This made their opinions matter, and their writing was no longer just a performance for the teacher.
Another example: my students in ENG 101 wrote research papers, as usual. Afterward, they had to make a Power Point presentation on their research so they could show their research to other classes and share it with our class. This move from a traditional paper into a different context and for a different purpose helped students understand how writing changes depending on the context and also made their research "portable" so they could use it again.