How about a user-input number or code that could be applied to each new message? I don't know what to call it, "Priority" was the closest I could think of.

Suppose a number from 0 to 5 could be used. For example, "0" could be for "Chatter", and for acknowledgements such as "Thanks, Ted, that worked". "5" could be for announcements of new MS service packs or downloads, bug reports, people requesting immediate help, etc.

This code would be strictly optional and would default to 0 if not filled in. It could perhaps be implemented via a dropdown next to the "Send/Preview" buttons.

By default, UT would appear as it does now; the user would have to choose to activate filtering/sorting based on "priority". However, this feature could essentially become a WHERE or ORDER BY clause for UT messages. It would be very nice if UT messages could them be sorted by the existing categories then sub-sorted by "priority", or by "priority" then by the existing categories. And/Or perhaps filtered to only show messages where "priority" > 0.