I think it would be useful to have the ability to insert a timestamp to Long Text fields. We use these fields for tracking activity and having a timestamp would make a huge difference. I envision it like a little calendar/clock icon next to the @ below the field, that when I click it inserts the current date/time (or I would even be able to pick which one to add)
I know that I could use comments, since they are timestamped; however, they are not truly part of the record as Long Texts are (as records copied via zap or in duplicate bases will not keep that info). Besides, they will get out of view as new activity is recorded in the history.