You haven't indicated why you chose to create a copy of a table just to join it to the original. Unless you're going to join in a way that causes a performance problem, creating a SELF JOIN isn't an inherently bad thing. So, how about:

SELECT *

FROM Announcements A1

INNER JOIN Announcements A2

ON A1.AnnouncementID = A2.AnnouncementID

Of course, with this query, you'll have two copies of every field in the original table showing up in the result set, and I'm not sure why you would want that, so you might want to elaborate on what your objective is.