You needn't use an external image hosting website - you can host them on our website. Click 'New Reply', then 'Choose File' underneath 'Attachments' and locate your image, then click 'Add Attachment'.
See attached image to see what the button looks like.

Hosting them on our website means that they're likely to remain forever (or at least for as long as NEB lives) and only members of the forum can view them.