The post i've gotten was
http://www.mikafanclub.com/forums/showpost.php?p=1021184
basically, I just asked the database to take every post that isn't marked as deleted, and give me the 1,000,000th entry. Of course, this number could technically change, and if a mod deletes a post that was BEFORE this one, the 1,000,000th post would go up to the next non-deleted record.
mysql> select postid, username,dateline from post where visible=1 limit 999999,1;
Current database: mikafanc_mikafanc
+---------+----------+------------+
| postid | username | dateline |
+---------+----------+------------+
| 1021184 | Ceci_B | 1199933482 |
+---------+----------+------------+
1 row in set (1.84 sec)
mysql>