To create an auto list, login, perform a query or an advanced query with the filters button, and then pull down from more actions to add the results of your query to your list. It will add maximum 50 per day.

It's written in 100% node.js - you can see the code here http://tweetbe.at/node/search.js

Code is shared between web client and the server, this is something that would have been nightmarish without node.js