I don't like how the results are refreshed ... it should load the results in a hidden div or something, then swap, and it should put a delta between refreshes ... I would have a second elapsed between 2 result sets displayed.

The indexer doesn't do a very good job, e.g. I searched for "mono" and only 4 results have been shown. Here's the Google index: http://www.google.ro/search?q=mono+site:news.ycombinator.com

Also, the address bar should be refreshed with the query searched because the URI has to be a permalink.

Otherwise, it's awesome.