Another thread on the dual-boxing forums pointed me towards the Therapist addon - http://www.wowinterface.com/download...Therapist.html

This is seriously tempting, for those people who are just completely ignorant pricks and delight in trying to make you miserable for doing something you find to be a little more challenging then default vanilla wow.
Most people are positive in their interactions with me regarding boxing on my server. I've actually run into around a dozen 5-boxing teams while playing one of my teams or another. While making my latest team, someone was setting up another team beside me, very neat stuff to see there are others on my server doing the same.
A few people are negative no matter what. Mostly I ignore them completely if they are very hostile. But this addon could be very useful in this situation.