Twitter is the latest web-centric communications service to explode onto the scene, and businesses have moved in rapidly. However, a little discretion goes a long way, as the users of “social” sites and services have demonstrated that they will stomach only so much commercialization of what they consider their personal space. As MySpace evolved from an upstart new kid on the block where everyone let everything “hang out” to a part of the Rupert Murdoch media empire, people who’d had enough began looking for other places. This influenced the rise of Facebook. Now that Facebook has begun acting like a “regular old corporation,” too, folks are on the search again…