Task and related lists

Is it possible to change the columns viewed for tasks?
For example: under any given opportunity/prospect I see a list of tasks that list gives me column headers of: Subject, Activity Type, Status and Owner
What has happened in my case is that my employees are using the Subject tab to write descriptions since this is the only way they can see these descriptions under this view. The problem with this is that when I run an activity report I get variations on E-Mail and Calls like (Email: Steve re: mapping) which make the reports useless. What I they should be doing is selecting a subject from the pull down menu when creating the task. If I could display the description in the related list report, I would not have this problem.