http://kligl.com/hnsearch/
I found some interesting posts when testing it:
http://kligl.com/hnsearch/#search+sort:old+type:comment+user...
led to
http://news.ycombinator.com/item?id=2459
Also this:
http://news.ycombinator.com/item?id=259132
Funny, that the idea of a search engine for the best 10k hackers from PG's essay on start-ip ideas is already 3 years old.
Another one:
http://kligl.com/hnsearch/#dropbox+sort:old+type:comment