Unfortunately, imho of course, the commercial APIs are over-represented and open formats and protocols are not represented at all. RSS will never offer you a job or fund your startup, but -- it might keep the Internet free so we'll still be interested in entrepreneurship for the Class of 2020 and beyond. You always have to keep putting back. And as the Twitter developers will tell you, the waters that surround big battleships and aircraft carriers can be very turbulent. As they say, when an 800-pound gorilla sneezes, you're the one with boogers all over you.
That's why I like platforms without platform vendors. There's no one to change the rules, decide that you've been copying them when they've been copying you. To deprecate the APIs that you've invested your life savings in.
Okay anyway, enough motivation.
The 11 free ideas are:
1. Share Your OPML.
2. Beautiful River.
3. UI for FeedHose.
4. Centralized subscription manager.
5. Hack status.net so we can template it.
6. What if Readability and Instapaper didn't have to scrape?
7. REST interface for DNS.
8. Open source Dropbox clone.
9. Drop-dead simple static hosting.
10. University news.
11. Make Apache an end-user product.
All are explained in more depth in two bits I wrote last fall.