I would also agree that this is an important feature so thanks for considering it.
I hacked this under Spark 1.0.3 by making the transcripts folder unwritable. The history is shown until the Spark client is shutdown. When restarted, the history is blank. I’'ve seen no ill effects using this technique.
If anyone wants specific steps needed to make the folder unwritable, just let me know.
Obviously, I preference setting would be, umm, preferable. How do people feel about a global setting that could be overridden on a contact-by-contact basis?
BTW, I’'m very excited about Spark and Wildfire and have had a lot of fun the past few days getting to know them. Kudos to the team!