You can link them. Just right click the image. Then select copy image location. Now go to the new thead. Click on the mountain icon and paste the image url. And voila.
I prefer imageshack. They dont have a bandwidth limit like photobucket does. Also they give you a thumbnail code, which a lot of people like.
In your usercp, you can view all your attachments. http://mmb.maverick.to/profile.php?do=editattachments Once you find your pic, you can link to it in your new thread.