How to display thumbnail image with the product.........

If you want something like user images on these pages
http://sphred.com/profile/1-Nasir-Jamal, http://sphred.com/profile/2-Amy-Gooch
(click on the user image to see) then you can use acts_as_attachment
plugin.

I have written the steps to set the whole thing here
http://nasir.wordpress.com/2007/10/28/how-to-get-file_column-plugin-working-on-mac-osx/