Similar to what I suggested
here
As several users are having the dredded red-x thumbnail for most files except jpeg or png, how about adding a couple of extra fields
Thumbnail - Here the user can upload another file which will act as the thumbnail if the main file produces the red-x pic.
Url direct - The uploaded pic acts as a thumb, then when clicked takes the user the the url located in this field. This way users can even add a links area where a pic represents the site it directs to. (kinda what was suggested in the thread I linked to above).
May come in handy for many users
Linear Mode
