Hi Mathias, basically there are several USP template tags for displaying submitted images, which are attached as custom fields to posts. One example, you could add this tag to the WP Loop:
Then there are parameters that can be specified to indicate size, set the number of images, and prepend/append text/markup before and after the image URL(s):
usp_post_attachments('thumbnail', '<img src="', '" />', false);
That will display all images attached to the current post, displayed as an image. More info on this tag (and others) in
@tgiokdi: good news! submitted images are also inserted into the WP Media Library, so no need to use USP tags at all -- you can use any WP tags needed to display the content.
Also should mention the Pro version of the plugin that does all of this and much more either automatically or with shortcodes and plugin settings: http://plugin-planet.com/