[jcfrei]

it's still nice but it's been here before: http://news.ycombinator.com/item?id=1835460

BTW: since there's no search feature to check for older posts, I suggest you use google: site:ycombinator.com

[ronnier]

I've also created an API to look up URLs that have been posted to HackerNews.

http://api.ihackernews.com/getid?url=http://uploads.unground...

[vanni]

Even earlier: http://news.ycombinator.com/item?id=1261816

[Stasyan]

searchyc.com

[tonyskn]

or http://www.backtype.com