The SharePoint Discussions List has long been a bone of contention within the SharePoint community. Whilst there are some excellent 3rd party solutions (such as Lightening Tools) you often have to just make do with the out-of-the-box list.

One strange feature of this list is that it isn’t possible to show who the Last Replier was in a view. This makes it next to impossible to quickly see if someone has replied to a thread you posted in (unless you can remember the number of posts in each thread).

This has probably got something to do with the fact that there are two content types in the list and the main one is not the actual discussion.

In any case, thanks to the discussion here, I’ve found a way to display who the last replier was in a view.

To add a Last Replier:

1. Add a User column called LastReplier to the Discussion list.
   Note: I never use spaces when adding columns – you can add the spaces later, for example, immediately after creating it!
2. Open the list in SharePoint Designer 2010 and click List Workflow | Project Discussions (or whatever your discussions list is called).
   
3. Give the workflow a name and a description and click OK.
   
4. Click Condition | If current item field equals value.
   
5. Click field and select Content Type.
   
6. Click Value and type in Message.
7. Click Action | Update List Item.
   
8. Click this list and select Current List from the menu.
   
9. Select ID from the field menu in the Find the List Item Section.
10. Select the Value field to Current Item Parent Folder Id.
    
11. Click Add and set the LastReplier field to Current Item:Modified By. 
    
12. Click OK.
    
13. Click the link to the Workflow on the breadcrumbs.
    
14. Ensure the Start Options are as below.
    
15. Click Publish.
    
    Now for some cleanup.
16. Return to the Discussion List and hide the Worfklow column from the main view – we assume you know how to do this.
    
17. Next, navigate to the list Settings page and click Column visibility settings (BrightWork).
    Note: Hiding the column in the forms just makes things easier for users; however, this is a BrightWork only feature – everything else in this post is vanilla SharePoint!
    
18. Unselect all the checkboxes for the Last Replier column and click OK.
    
    
    And voila – when a user replies to one of your posts, you will be able to see it.