Instead of required blog posts or reading quizzes, I require my students to interact with each week's reading and each other by "live-tweeting" their reading process.
By creating their own Twitter accounts and finding accounts to follow that are related to their research topic, students learn the difference between library resources and online resources like daily news, blogs, and opinion.
Using the multimedia curation program, Storify, students compose a short writing assignment analyzing an "author's" ethos based on his or her Twitter feed. This demonstrates the ways in which ethos is cultivated over time and in a variety of different ways.
My class used Twitter for a few general purposes and then for two specific assignments. For our general goals, we used Twitter to share resources among one another and to familiarize ourselves with various conversations that are important to people in the digital humanities.