VBA: Automatically Changing sheet structure

I've got a rather large spread sheet that has multiple users for same items. I've got the all the users listed in one column with the items listed in the next column. There is no difference in the items and they are simply duplicate information for the user listing. I orginally thought this was fine so I could filter the list by the user catagory and have each user's own item listing. Now that the list is so large and the item duplication is a pain, I want to list the items only once and somehow retain all the users for the item. Currently, for each entry I am copying and pasting the original data tand changing the user name. (I know, I know). "need a little help"