Nino - are people better linking photos rather than attaching them. Eg: use the image link function within photobucket? Do these still come under 'attachments' in the 10GB limit?
Links to external sites won't be affected. The link button actually points to the photos hosted on picture sites. All my restorations are hosted on AP, and they take up 750 Meg. But they will all be moved and are not part of the attachments directory structure.
It is preferable for members to host their pictures externally if they want to keep the photos embedded in the threads. In my case, i have to move them and then edit every single post on all restoration threads. I'll do that once we have made it to the first stage - culling the attachment directory !
To answer your question - images hosted externally, and linked within the posts do not affect the attachments directory on the AP Host at all.