Macho...

I can't speak for the sites you listed specifically, but there are pre packaged scripts available that handle what those sites do.

Most are template driven and customizable, if you're looking to open on yourself.

Depending on the site, they can be great sources of traffic for both the owner and the submitter. But I tend to think the owner of the site probably makes out better.

I'm not sure what else you're looking for so I'll stop here. Let me know what other question you have...

Gary-Alan