Personally I don't use sites like you described. Inevitably, the links, images, etc... that get ranked aren't links, images, etc... that I want to see.
Perhaps if there was a way to filter the links, images, etc... by date updated (or freshness), perhaps it would be somewhat useful.
From a web developer perspective, I wouldn't mind the extra link back to my site.
As with all things web related, just give it a try and see how it turns out. Not a lot of investment involved other than some of your time (and maybe a little bit for hosting).
By the sound of things, you're asking for ideas; which can be good, but makes me believe you're not sure what you want from the site. You've got a general idea, but you need to make your personal goals for the site and focus on them.
Then ask for advice once you've met your own goals (which, you'll never do - you'll always make new ones).