I believe this pipe is public:
http://pipes.yahoo.com/pipes/pipe.in...3RGmawspQBJ3AQ <-- non flyertalk pulls in other sources, the pipe it pulls in is another Hopper pipe that parses a Hopper RSS feed. I've not yet figured out how to filter by price so its not so useful since its just a list of destinations and prices from Hopper.
http://pipes.yahoo.com/pipes/pipe.in...2742b511f2bdd9 <-- flyertalk only, filters on some airports and users names, also it looks like this flyertalk pipe might be one that I coned myself

You can view that pipe and edit it if you have a yahoo account. You probably need to clone the pipe, then edit or view source and in a GUI you can edit how its setup. Then you could bookmark the pipe, or pull it into an rss reader via the Get as RSS link when you run the pipe.

Also if you do a search on http://pipes.yahoo.com/ for flyertalk you will find more examples