The url of an existing post looks like this:
In my example, here, 7008 is the number of that post.
To edit one of your existing posts, change the url like this:
From http://www.digitalmanga.com/forums/viewtopic.php?f=56&t=1398&p=7008#p7008 to http://www.digitalmanga.com/forums/posting.php?mode=edit&f=56&p=7008
This will only work in The Guild Guide subforum because of that "f=56" tag in the URL. If you want to do this in another forum, you need to use the id number for that subforum. [New: To edit your posts in the Group Search subforum, the correct tag is "f=58"] [New New: I've found I can edit in the Group Search subforum no matter what the f number is. Bizarre. ]And of course, it only works on your own posts. Silly.
Enjoy your newfound freedom!