You can just as easily go to the person's profile and click all threads made by this user.Quite a bit, too.
Not only that, you can tag your own threads and categorise them, so it does make searching a little easier. You can, for example, search for a tag "x42bn6" and it will give you all threads made by me, all threads with me in the title and all threads tagged "x42bn6".
There might be some uses later. At the moment, I think it is still indexing the whole of the forums.*