I also use Photobucket to post my photos. In order to post direct images, once you've uploaded a photo, click the "Share" button on the top border of the photo. Next, click "Get Link Code", then find the code that says "IMG for bulletin boards & forums". Copy the top code that begins with , and then paste the same link into any post on the forum.
Example:
Linking to the photo:
[URL]http://s903.photobucket.com/albums/ac237/Carfreak4/CSX%20Trainz/?action=view¤t=trainz2010-08-0917-02-47-28.jpg&newest=1[/URL]
Sharing the photo using the [IMG] code:
[IMG]http://i903.photobucket.com/albums/ac237/Carfreak4/CSX%20Trainz/trainz2010-08-0917-02-47-28.jpg
Hope this helps.
Carfreak4