This app was inspired by some work I did for a non-profit conference that was looking to let its attendees add themselves to Twitter lists, rather than rely on them to remember to use the correct hashtag. It was a long weekend of work, but it's gotten some decent use.<p>The premise is simple: The app allows you to create a simple portal where users can add themselves to Twitter lists that you designate 'Open'.<p>So, for the account @Crowdlistr and the twitter list @sample, people can add themselves from here: <a href="http://crowdlistr.com/crowdlistr/sample" rel="nofollow">http://crowdlistr.com/crowdlistr/sample</a><p>Let me know if you have any questions or suggestions (beyond telling me that the design sucks, because, well, the design sucks.)