First thing I have not said anything about flickr or del.icio.us recently but there very good ideas and well excuted. i think even Jon Udell is happy with these RESTful/web services/applications? In my view anything which creates semantic-ish meaning is good. Some things which I've seen recently.
ebay to rss
another one, rss auction
Google to Atom
Netflix's rss feeds
iTunes music store rss feed generator
iTunes playlist to RSS
When's imdb going to do rss?. Now owned by Amazon they must have syndication in there future plans. I mean it wasnt long ago when imdb would allow you to copy there databases?