Very interesting. I believe a similar function could be built in to the browsers using the custom search functionality if one can figure out how to implement multi-parameter queries. I think chrome doesn't allow this[1] but it is possible on firefox [2].
I know one way I would use this --
On chrome I have 'rr' set to go to the subreddit following it; and have 'r' set to simply search all of reddit. It would be great if there was someway to specify two parameters one - the subreddit I am searching and two - the search terms I want to search for within that subreddit.
[1] https://stackoverflow.com/questions/10265777/how-can-i-do-mu...
[2] http://kb.mozillazine.org/Multiple_parameter_keyword_searche...
